Which sins are equivalent to or even greater than Brahmhatya?

Question

Brahmhatya is a very grave sin , and is frequently used as a parameter to judge other sins. Which other sins are equivalent to or greater than Brahmhatya ?

Answer 1

Since brahmahatyā is considered 1 out of the 5 mahāpātakas, we can consider the other 4 to be of equivalent sin.

ब्रह्महत्या सुरापानं स्तेयं गुर्वङ्गनागमः । महान्ति पातकान्याहुः संयोगश्चेव तैः सह ।। अनृते च समुत्कर्षो राजगामि च पैशुनम् । गुरोश्चालीकनिर्बन्धः समान ब्रह्महत्यया ।। ब्रह्मोज्झ्यवेदनिन्दा च कौटसाक्ष्यं सुहृद्वधः । गर्हितान्नाज्ययोर्जग्धिः सुरापानसमानि षट् ।। निक्षेपस्यापहरणं नराश्चरजतस्य च । भूमिवज्रमणीनां च रुक्मस्तेयसमं स्मृतम् ।। रेतः सेकः स्वयोनीषु कुमारीष्वन्त्यजासु च । सख्युः पुत्रस्य च स्त्रीषु गुरुतल्पसमं विदुः ।।

Translation: (Said to Paraśurāma by Puṣkara which he had heard from his father Varuṇa) Killing a brāhmaṇa, alcohol consumption, stealing (gold), sex with the guru's wife & company of those who perpetrate these are considered as great sins. Encouraging lawlessness, serving the monarch, back-biting, slandering the guru - these are equivalent to killing a brāhmaṇa. Abandoning the Veda, criticising the Veda, giving false testimony, murdering one's own friend, eating censured food & ghee - these 6 acts are equivalent to alcohol consumption. Stealing that which has been pawned, men, horses, silver, land, diamonds & gems are equivalent to stealing gold. Inseminating a woman belonging to one's own kin, (unmarried) virgins, outcaste women, women belonging to the family of one's own friend & son are considered to be equivalent of violating the guru's bed by the wise men. [Agnipurāṇa:168:24-28]

Devībhāgavatapurāṇa also compares the following with brahmahatyā

श्रीकृष्णे च तदर्चायामन्येषां प्रकृतौ सति । शिवे च शिवलिङ्‌गे च सूर्ये सूर्यमणौ तथा ॥ गणेशे वाथ दुर्गायामेवं सर्वत्र सुन्दरि । यः करोति भेदबुद्धिं ब्रह्महत्यां लभेत्तु सः ॥ स्वगुरौ स्वेष्टदेवे च जन्मदातरि मातरि । करोति भेदबुद्धिं यो ब्रह्महत्यां लभेत्तु सः ॥ वैष्णवेषु च भक्तेषु ब्राह्मणेष्वितरेषु च । करोति भेदबुद्धिं यो ब्रह्महत्यां लभेत्तु सः ॥ विप्रपादोदके चैव शालग्रामोदके तथा । करोति भेदबुद्धिं यो ब्रह्महत्यां लभेत्तु सः ॥ शिवनैवेद्यके चैव हरिनैवेद्यके तथा । करोति भेदबुद्धिं यो ब्रह्महत्यां लभेत्तु सः ॥ सर्वेश्वरेश्वरे कृष्णे सर्वकारणकारणे । सर्वाद्ये सर्वदेवानां सेव्ये सर्वान्तरात्मनि ॥ माययानेकरूपे वाप्येक एव हि निर्गुणे । करोतीशेन भेदं यो ब्रह्महत्यां लभेत्तु सः ॥ शक्तिभक्ते द्वेषबुद्धिं शक्तिशास्त्रे तथैव च । द्वेषं यः कुरुते मर्त्यो ब्रह्महत्यां लभेत्तु सः ॥ पितृदेवार्चनं यो वा त्यजेद्वेदनिरूपितम् । यः करोति निषिद्धं च ब्रह्महत्यां लभेत्तु सः ॥ यो निन्दति हृषीकेशं तन्मन्त्रोपासकं तथा । पवित्राणां पवित्रं च ज्ञानानन्दं सनातनम् ॥ प्रधानं वैष्णवानां च देवानां सेव्यमीश्वरम् । ये नार्चयन्ति निन्दन्ति ब्रह्महत्यां लभन्ति ते ॥ ये निन्दन्ति महादेवीं कारणब्रह्मरूपिणीम् । सर्वशक्तिस्वरूपां च प्रकृतिं सर्वमातरम् ॥ सर्वदेवस्वरूपां च सर्वेषां वन्दितां सदा । सर्वकारणरूपां च ब्रह्महत्यां लभन्ति ते ॥ कृष्णजन्माष्टमीं रामनवमीं च सुपुण्यदाम् । शिवरात्रिं तथा चैकादशीं वारे रवेस्तथा ॥ पञ्च पर्वाणि पुण्यानि ये न कुर्वन्ति मानवाः । लभन्ति ब्रह्महत्यां ते चण्डालाधिकपापिनः ॥ अम्बुवाच्यां भूखननं जलशौचादिकं च ये । कुर्वन्ति भारते वर्षे ब्रह्महत्यां लभन्ति ते ॥ गुरुञ्च मातरं तातं साध्वीं भार्यां सुतं सुताम् । अनिन्द्यां यो न पुष्णाति ब्रह्महत्यां लभेत्तु सः ॥ विवाहो यस्य न भवेन्न पश्यति सुतं तु यः । हरिभक्तिविहीनो यो ब्रह्महत्यां लभेत्तु सः ॥ हरेरनैवेद्यभोजी नित्यं विष्णुं न पूजयेत् । पुण्यं पार्थिवलिङ्‌गं च ब्रह्महासौ प्रकीर्तितः ॥

Translation : (Said by Yama to Sāvitrī) O Chaste & Beautiful One ! He who makes a distinction between Śrīkṛṣṇa & His (duly consecrated) icon, Śiva & (duly consecrated) śivaliṅga, Sūrya & star-ruby, Gaṇeśa & His (duly consecrated) icon, Durgā & Her (duly consecrated) icon, all other deities & their respective (duly consecrated) icons earns the sin of brahmahatyā. He who makes a distinction between his Iṣṭa, guru, father & mother earns the sin of brahmahatyā. He who makes a distinction between Vaiṣṇavas, devotees of other deities & brāhmaṇas earns the sin of brahmahatyā. He who makes a distinction between the water used to wash the feet of the brāhmaṇa & that used to bathe a Śālagrāma śilā earns the sin of brahmahatyā. He who makes a distinction between the naivedyas of Hari & Śiva earns the sin of brahmahatyā. He who makes a distinction between Kṛṣṇa, the master of all masters, the cause of all causes, the first amongst all, who is served by all devas, the inner soul of all, who is One but spread across various forms assumed through illusion & the Nirguṇa Lord earns the sin of brahmahatyā. He who in this world harbours hatred for the devotees of Śakti & similarly hates the Śakti-centric scriptures earns the sin of brahmahatyā. He who abandons the worship of the devas & pitṛs as determined by the Veda & makes them prohibited earns the sin of brahmahatyā. He who abuses Hṛṣīkeśa & those initiated into His mantra, those who abuse & never worship Iśvara, the holiest among the holy, the (personified) bliss of knowledge, the eternal one, the chief of the Vaiṣṇavas, served by all the devas - all of them earn the sin of brahmahatyā. Those who abuse the the great Devī who is the of the form of the causative Brahman, who is the embodiment of all power, who is Prakṛti, the mother of all, who is the embodiment of all the devas, who is ever worshipped by all, who embodies all causes attain the sin of brahmahatyā. The people who don't observe holy vows on the occasion of Janmāṣṭamī, the merit-bestowing Rāmanavamī, Śivarātri, ekādaśī, Sundays & the 5 holy days (aṣṭamī, caturdaśī, new-moon, full-moon & saṁkrānti) earn the sin of brahmahatyā & are considered to be more sinful than caṇḍālas. Those who dig the earth & perform ācamana with water on the day of Ambuvācī in Bhāratavarṣa earn the sin of brahmahatyā. He who doesn't supports his faultless guru, mother, father, chaste wife, son & daughter earns the sin of brahmahatyā. If the man devoid of devotion to Hari doesn't marries & doesn't sees the face of his progeny, then he earns the sin of brahmahatyā. He who always eats food that hasn't been offered to Hari & not worships Hari & the holy earthen liṅga is said to be a slayer of brāhmaṇa.[Devībhāgavatapurāṇa:9:34:32-51]

Skandapurāṇa states

मार्गभेदी स्वार्थपाकी यतिब्राह्मणदूषकः । अत्याशी वेदविक्रेता पञ्चैते ब्रह्मघातकाः ।। ब्राह्मणान्यः समाहूय दास्यामीति धनादिकम् । पश्चान्नास्तीति यो ब्रूते ब्रह्महा सोऽपि कीर्तितः ।। परिज्ञाय यतो धर्मांस्तस्मै यो द्वेषमाचरेत् । अवजानाति वा विप्रान्ब्रह्महा सोऽपि कीर्तितः ।। जलपानार्थमायातं गोवृन्दं तु जलाशये । निवारयति यो विप्रा ब्रह्महा सोऽपि कीर्तितः ।। सेतुमेत्य तु ते सर्वे मुच्यन्ते दोषसञ्चयैः । ब्रह्मघातकतुल्या ये सन्ति चान्ये द्विजोत्तमाः ।। ते सर्वे सेतुमागत्य मुच्यन्ते नात्र संशयः । औपासनपरित्यागी देवतान्नस्य भोजकः ।। सुरापयोषित्संसर्गी गणिकान्नाशनस्तथा । गणान्नभोजकश्चैव पतितान्नरतश्च यः ।। एते सुरापिनः प्रोक्ताः सर्वकर्मबहिष्कृताः । सेतुस्नानेन मुच्यन्ते ते सर्वे हतकिल्बिषाः ।। सुरापतुल्या ये चान्ये मुच्यन्ते सेतुमज्जनात् । कन्दमूलफलानां च कस्तूरीपट्टवाससाम् ।। पयश्चन्दनकर्पूरक्रमुकाणां तथैव च । मध्वाज्यताम्रकांस्यानां रुद्राक्षाणां तथैव च ।। चोरकास्तु परिज्ञेया सुवर्णस्तेयिनः समाः । ते सेतुक्षेत्रमागत्य मुच्यन्ते नात्र संशयः ।। अन्ये च स्तेयिनः सर्वे सेतुस्नानेन वै द्विजाः । मुच्यन्ते सर्वपापेभ्यो नात्र कार्या विचारणा ।। भगिनीं पुत्रभार्यां च तथैव च रजस्वलाम् । भ्रातृभार्यां मित्रभार्यां मद्यपां च परस्त्रियम् ।। हीनस्त्रियं च विश्वस्तां योऽभिगच्छतिरागतः । गुरुतल्पी स विज्ञेयः सर्वकर्मबहिष्कृतः ।। एते चान्ये च ये सन्ति गुरुतल्पगतुल्यकाः । ते सर्वे प्रविमुच्यन्ते सेतुस्नानेन वै द्विजाः ।। एतैः संसर्गिणो विप्रा ये चान्ये सन्ति पापिनः । सेतुस्नानेन महता तेऽपि मोक्षमवाप्नुयुः ।।

Translation:(Said by Sūta to the sages of Naimiṣāraṇya) The destroyer of roadways, one who cooks only for his own self (i.e doesn't performs the pañcayajñas), one who pollutes ascetics (by causing them to renounce ascetism) & brāhmaṇas (by causing them to abandon brāhmaṇya), a glutton & a seller of the Veda (i.e who indiscriminately imparts religious knowledge with the sole aim to earn money) - these 5 are known as slayer of brāhmaṇas. The person who pledges to donate money to one brāhmaṇa but later says 'No' (i.e renegades on his promise) is also known as a brāhmaṇa-slayer. He who harbours hatred against his religious instructor & abuses brāhmaṇas is also known as a brāhmaṇa-slayer. The brāhmaṇa who prevents cattle that have arrived near a waterbody from drinking water is also known as a brāhmaṇa-slayer. Such people are freed of these accumulated sins by visiting Setubandha (Rāmeśvaram). O best amongst the dvijas ! Undoubtedly people get released from these other sins equivalent to brahmahatyā on arriving at Setubandha. Those who abandon the rites of worship (of devas & pitṛs), eat the food meant to be offered to the devas, interact with an intoxication-addicted woman, eat the food offered by prostitutes, eat the food meant for mass consumption, eat the food offered by degraded people are considered as alcohics & are to be excluded from all sorts of holy activities. All such sins are destroyed & the sinners equivalent to alcoholics are liberated by performing an ablution at Setubandha. Those who steal bulbous roots, roots, deer-musk, silken cloth, water, sandalwood, camphor, areca-nut, honey, ghee,copper, brass, rudrākṣas (in short materials to be used in a pūjā ceremony) are considered equivalent to stealers of gold (from brāhmaṇas). Undoubtedly such people are released (from sin) on arriving at Setubandha. O dvijas ! You shouldn't doubt over the fact that all those who steal other objects also get released from all sorts of sins by performing ablutions at Setubandha. He who indulges in sex with one's own sister, daughter-in-law, menstruating wife, sister-in-law, friend's wife, intoxicated women, wives of others & in a fit of rage women who had placed their trust on him is considered as a violater of the gurupatnī & is to be excluded from all sorts of holy-rites. O dvijas ! Such people who are considered equivalent to those who indulge in sex with gurupatnī are released from their sins by performing ablutions at Setubandha. O great vipras ! Even those who keep company with such people & other such sinners do obtain mokṣa by performing ablutions at Setubandha. [Skandapurāṇa : Brāhmakhaṇḍa : Setumāhatmya:1:53-68]

Brahmāṇḍapurāṇa states

भूपद्विजश्रोत्रियवेदविद्व्रतीवेदान्तविद्वेदविदां विनाशे । एकद्विपञ्चाशदथायुतं च स्यान्निष्कृतिश्चेति वदन्ति सन्त ।।

Translation:(Said by Bṛhaspati to Indra) The wise tell that one gets liberated from the sin of killing a monarch, a śrotriya brāhmaṇa a scholar of the Veda who performs vows, a scholar of the Veda who also knows Vedānta (by performing the prāyaścitta) in the order of 1,2, 50 & 10,000. [Brahmāṇḍapurāṇa:Lalitopākhyāna:6:48]

पापानामधिकं पापं हननं जीवजातिनाम् । एतस्मादधिकं पापं विश्वस्ते शरणं गते ।। विश्वस्तं हत्वा पापिष्ठं शूद्रं वाप्यन्त्यजातिजम् । ब्रह्महत्याधिकं पापं तस्मान्नास्तस्य निष्कृतिः ।। ब्रह्मज्ञस्य दरिद्रस्य कृच्छ्रार्जितधनस्य च । बहुपुत्रकलत्रस्य तेन जीवितुमिच्छतः । तद्द्रव्यस्तेयदोषस्य प्रायश्चित्तं न विद्यते ।। विश्वस्तद्रव्यहरणं तस्याप्यधिकमुच्यते । विश्वस्ते वाप्यविश्यस्ते न दरिद्रधनं हरेत् ।। ततो देवद्विजातीनां हेमरत्नापहारकम् । यो हन्यादविचारेण सोऽश्वमेधफलं लभेत् ।।

Translation:(Said by Bṛhaspati to Indra) To kill living beings is a sin greater than all other sins. Even more sinful among them is to kill a trusted person who has sought refuge. The sinner who kills a trusted person earns a sin greater than the murder of a brāhmaṇa even if the person killed is a śūdra or an untouchable & there is no prāyaścitta for it. (Similarly) there is no prāyaścitta for stealing goods belonging to a knower of Brahman, a poor person, one who earns money through hardwork, one who has multiple children & wives (to sustain) & one who desires to live through it (i.e money for medical treatment or bribing would-be assassins & tools whose absence renders the execution of a particular profession completely impossible like the potter's wheel for a potter, fishing net for fishermen, ink & paper for a record-keeper & so on). Even more (sinful) is said to be the theft of goods belonging to a trusted person. One should never steal from the poor, whether the person is trusted or not. Similarly those who kill the stealer of gold & gems belonging to devas & brāhmaṇas even unjustly earn the merit of having performed Aśvamedha. [Brahmāṇḍapurāṇa:Lalitopākhyāna:7:2-6]

Shivapurāṇa states

ब्राह्मणं यः समाहूय दत्त्वा यश्चाददाति च । निर्द्दोषं दूषयेद्यस्तु स नरो ब्रह्महा भवेत् ।। यश्च विद्याभिमानेन निस्तेजयति सुद्विजम् । उदासीनं सभामध्ये ब्रह्महा स प्रकीर्तितः ।। मिथ्यागुणैर्य आत्मानं नयत्युत्कर्षतां बलात् । गुणानपि निरुद्वास्य स च वै ब्रह्महा भवेत् ।। गवां वृषाभिभूतानां द्विजानां गुरुपूर्वकम् । यस्समाचरते विप्र तमाहुर्ब्रह्मघातकम् ।। देवद्विजगवां भूमिं प्रदत्तां हरते तु यः । प्रनष्टामपि कालेन तमाहुर्ब्रह्मघातकम् ।। देवद्विजस्वहरणमन्यायेनार्जितं तु यत् । ब्रह्महत्यासमं ज्ञेयं पातकं नात्र संशयः ।। अधीत्य यो द्विजो वेदं ब्रह्मज्ञानं शिवात्मकम् । यदि त्यजति यो मूढ़ः सुरापानस्य तत्समम् ।। यत्किञ्चिद्धि व्रतं गृह्य नियमं यजनं तथा । संत्यागः पञ्चयज्ञानां सुरापानस्य तत्समम् ।। पितृमातृपरित्यागः कूटसाक्ष्यं द्विजानृतम् । आमिषं शिवभक्तानामभक्ष्यस्य च भक्षणम् ।। वने निरपराधानां प्राणिनां चापघातनम् । द्विजार्थं प्रक्षिपेत्साधुर्न धर्मार्थं नियोजयेत् ।। गवां मार्गे वने ग्रामे यैश्चैवाग्निः प्रदीयते । इति पापानि घोराणि ब्रह्महत्यासमानि च ।। दीनसर्वस्वहरणं नरस्त्रीगजवाजिनाम् । गोभूरजतवस्त्राणामौषधीनां रसस्य च ।। चन्दनागरुकर्पूरकस्तूरीपट्टवाससाम्। विक्रयस्त्वविपत्तौ यः कृतो ज्ञानाद् द्विजातिभिः ।। हस्तन्यासापहरणं रुक्मस्तेयसमं स्मृतम् । कन्यानां वरयोग्यानामदानं सदृशे वरे ।। पुत्रमित्रकलत्रेषु गमनं भगिनीषु च । कुमारीसाहसं घोरमद्यपस्त्रीनिषेवणम् ।। सवर्णायाश्च गमनं गुरुभार्यासमं स्मृतम् । महापापानि चोक्तानि शृणु त्वमुपपातकम् ।।

Translation: He who invites a brāhmaṇa with the intention to give alms but doesn't gives the same & he who falsely accuses innocent people -that man becomes a slayer of brāhmaṇas. He, who out of vanity for his knowledge , humiliates a good dvija who remains silent in the assembly is known as a killer of brāhmaṇas. He who elevates himself through force by attributing to pretended virtues & tries to subdue talents is known as a killer of brāhmaṇas. O vipra ! He who obstructs cows attracted to bulls (i.e obstructs sex between a cow & a bull) & dvijas attracted to the guru (i.e prevents them from meeting with their gurus) is known as a killer of brāhmaṇas. He who snatches away land gifted to devas, brāhmaṇas & cattle even though it has been destroyed in the course of time is known as a killer of brāhmaṇas. The sin of stealing that which belongs to devas & dvijas & to earn through unfair means is undoubtedly considered to be on par with brahmahatyā. If a dvija abandons the Veda & knowlege of Brahman of the nature of Śiva after studying it (i.e commits apostasy), then that fool earns the sin equivalent to alcohol consumption. Abandonment of whatever holy vows that were undertaken, (scripturally-sanctioned) rules, worship & pañcayajñas is considered equivalent to alcohol-consumption. Abandoning one's own father & mother, give false testimony, lying to dvijas, consumption of non-vegetarian food by devotees of Śiva, eating unedible (i.e prohibited) food, killing innocent wild animals in forests, setting fire to pathways used by cows, forests & villages - these grave sins are considered to be equivalent to brahmahatyā. Good men should cast away the money meant for dvijas & shouldn't use the same for religious purposes. Stealing away all the belongings of the poor, men, women, elephants, horses, cattle, land, silver, clothes, juice of medicinal plants, sandalwood, aguru, camphor, musk, silk clothes, sale of the same (i.e stolen goods) in times of non-distress knowingly by dvijas, theft of money deposited to one's own self - these are considered equivalent to stealing gold. Not marrying off marriageable daughters to similarly (eligible) grooms (N.B in ancient times, it was believed that longer the time a father kept his daughter unmarried, greater was the chance of the daughter becoming unchaste), indulging in sex with the wives of one's friends, daughters-in-law, sisters, heavily-intoxicated women, sagotra women & raping virgins - these are considered equivalent to indulging in sex with gurupatni. I have told you the mahapāpas, now you hear about the upapātakas.[Shivapurāṇa:Umāsaṁhitā:5:25-40]

Padmapurāṇa roughly follows the list mentioned in Śivapurāṇa but adds

क्षुत्तृषातप्तदेहानामन्नभोजनमिच्छताम् । यः समाचरते विघ्नं तमाहुर्ब्रह्मघातकम् ॥ पिशुनः सर्वलोकानां रन्ध्रान्वेषणतत्परः । उद्वेजनकरः क्रूरः स च वै ब्रह्महा स्मृतः ॥

Translation: (Said to Yayāti by Mātali) He who creates obstacles for those whose bodies have been scorched by the (pangs of) hunger & thirst and wants to eat food (i.e prevents such people from accesing food) is known as a killer of brāhmaṇas. The cruel person who indulges in back-biting, finding weaknesses & causing trouble for everybody is also known as a killer of brāhmaṇas. [Padmapurāṇa:2:67:55-56]

Quoting (now lost) Cyavanasmṛti, Śūlapāṇi (a famous nibandhakāra from Bengal) states in his Prāyaścittaviveka that in place of alcohol consumption

1. Punishing the innocent & fleeing from the battlefield are mahāpātakas for kṣatriyas,
2. Cheating people by using faulty scales & weights is the mahāpātaka for vaiśyas
3. Selling meat (without being born into a fisherman, hunter or fowler family), drinking the milk of a tawny/Kapilā cow & sex with a brāhmaṇī are mahāpātakas for śūdras.

Quoting (now lost) Devalasmṛti, Śūlapāṇi states that

1. Killing one's own guru, father, mother, pregnant women & causing abortion is more dreadful than killing brāhmaṇas.
2. Stealing gold belonging to brāhmaṇas who observe month-long fasts, Somayajña & Agnihotra is more dreadful than stealing gold from any other person
3. Indulging in sex with the wife of the teacher (one who imparts both secular & religious knowledge in exchange of money), monarch & step-mother is more dreadful than indulging in sex with the wife of the guru (one who imparts only religious knowledge voluntarily without necessarily accepting money)
4. Consumption of Pauṣṭīka (made from grains like whiskey, ale, beer & rice-beer), Gauṛī (made from molasses like rum) & Mādhvī (made from honey like mead & mahua) varieties of alcohol is more dreadful than consumption of any other variety of alcohol (made from fruit-extracts like wine, toddy, feni, brandy, gin & cider).
5. Having sexual, social & economic contact with those who commit mahāpātakas is more dreadful than having mere physical contact with them.

Quoting (now lost) Paiṭhīnasismṛti, Śūlapāṇi states that killing the guru, causing abortion & killing one's own husband are sins that afflict womenfolk. Giving the fact that the previous 2 are already considered to be graver than brahmahatyā, we can safely say that the 3rd one i.e mariticide is also considered to more sinful than killing brāhmaṇas.

Quoting Viṣṇusmṛti, Śūlapāṇī also states about atipātakas, sins more dreadful than mahāpātakas and anupātakas, sins that lie between mahāpātakas & upapātakas.

The atipātakas are

1. Indulging in sex with one's own mother (Śūlapāṇi interprets this line to mean that indulging in sex with brāhmaṇī can also be considered an atipātaka for a śūdra because according to other scriptures, brāhmaṇa women are to be respected on the same level as one's own mother by śūdras, thereby explaining the extreme disdain for the caṇḍāla, who is said to be the product of such a union)
2. Indulging in sex with one's own sisters
3. Indulging in sex with one's own daughters

The only prāyaścitta for such acts is to cut-off one's genitals & die from the resulting blood-loss. Other sources prescribe being burnt alive as prāyaścitta.

The anupātakas are

1. Indulging in sex with step-mothers
2. Indulging in sex with wives of one's own paternal uncle
3. Indulging in sex with wives of one's own maternal grandfather
4. Indulging in sex with sagotra women (except one's own lawfully married wife)
5. Indulging in sex with wives of of one's own maternal uncle
6. Indulging in sex with wives of one's own father-in-law
7. Indulging in sex with wives of one's own maternal uncle
8. Indulging in sex with one's own father's sisters
9. Indulging in sex with one's own mother's sisters
10. Indulging in sex with wives of one's own friends
11. Indulging in sex with unmarried virgins
12. Indulging in sex with untouchable women
13. Indulging in sex with the friends of one's own sisters
14. Indulging in sex with women while they are menstruating
15. Indulging in sex with renunciate women
16. Indulging in sex with abandoned (i.e divorced) women

Devībhāgavatapurāṇa gives a slightly different opinion

गुरुपत्‍नीं राजपत्‍नीं सपत्‍नीं मातरं ध्रुवम् । सुतां पुत्रवधूं श्वश्रूं सगर्भां भगिनीं सतीम् ॥ सहोदरभ्रातृजायां मातुलानीं पितुः प्रसूम् । मातुः प्रसूं तत्स्वसारं भगिनीं भ्रातृकन्यकाम् ॥ शिष्यां शिष्यस्य पत्‍नीं च भागिनेयस्य कामिनीम् । भ्रातुः पुत्रप्रियां चैवात्यगम्या आह पद्मजः ॥ एताः कामेन कान्ता यो व्रजेद्वै मानवाधमः । स मातृगामी वेदेषु ब्रह्महत्याशतं व्रजेत् ॥ अकर्मार्होऽप्यसंस्पृश्यो लोके वेदे च निन्दितः । स याति कुम्भीपाके च महापापी सुदुष्करे ॥

Translation:(Said by Yama to Sāvitrī) The Gurupatnī, wife of the monarch, mother who is a co-wife (i.e step-mother), daughter, daughter-in-law, mother-in-law, sister who is born of the same womb, wife of the brother who is born of the same womb, maternal aunt, paternal grandmother, maternal grandmother, mother's sister, sisters residing in the same house (i.e step-sisters), brother's daughter, śiṣyā, wife of the śiṣya, maternal niece-in-law, paternal niece-in-law are surely designated by the Lotus-born One (i.e Brahmā) as atyāgamyā (extremely unfit to be approached for sex). The vilest of men who approaches these women out of lust is considered to have indulged in sex with his own mother & having committed brahmahatyā hundred times. He is determined in the Veda to be unfit for performing any holy act, untouchable & vilified. Ultimately that great sinner goes into the dreadful (hell-pit named) Kumbhīpāka. [Devībhāgavatapurāṇa:9:34:77-81]

The prāyaścitta for these sins are same as that of mahāpātakas.

Śūlapāṇi states that only those who are excluded from all sorts of holy-rites (i.e mlecchas) can live without performing any prāyaścitta for atipātakas, mahāpātakas, anupātakas & upapātakas.