Source: here.
The great brAhmaNa vAchaspati mishra, who was described as “sarva
tantra svatantra” provides a model that is equivalent to the 3D
cartesian system in his work nyAya vartika tAtparya TIkA (4.2.25) to
describe molecular/atomic contacs. The 3 axes were termed
pUrva-pashchima, uttara-dakShiNa and urdhva-adhara. The position of
any point is given by measuring the the distance along these
direction. The position of contacts between atoms can then be given as
numerical series of these coordinates.
ekatve.api dishaH Adityodayadesha pratyAsanadesha saMyukto yaH sa
itarasmAd viprakR^iShTa pradesha saMyogAt paramANoH purva
evamAdityAsta mayadesha pratyAsanadesha saMyukto yaH sa itarasmAd
viprakR^iShTa desha saMyogAt paramANoH pashchimaH tau cha
pUrvapashschimau paramANU apekSya yaH sUryOdayAstamayadesha
viprakR^iShTa desha sa madhyavatIM
evam etayoryau tiryagdesha saMbandhinau madhyasya Arjavena
vyavasthitau pArshvavartinau tau dakShiNottarau paramANU
evaM madhyandina vartisUryasanikarSha viprakarShau apekSha
uparyadhobhAvo draShTavyaH
samyukta saMyogAlpatva bhUyastave cha sanikarSha viprakarShau
pUrvasamkhyAvacchinntvaM va alpatvaM parasamkhyAvacchinnatvaM ca
bhUyastvaM