An x-ray molecular level structural characterization of Tertiary origin subbituminous Indian coal is reported in this paper with an attempt to better understand itsmolecular level structure, the short-range structural features, to determine the relationship (s) between the aryl / alkyl carbon ratio and determination ð and ã-bands positions of the coal. The coal was collected fromTirap colliery ofAssam,North-East India has been studied. The average poly-cyclic aromatic unit in Tirap coal is a ribbon-shaped C14 (analogous to phenanthracene). For this coal, the average carbon atoms (ncc) is found to be 1.24. Also, 73% of the C-C bonds in the coal are between aryl carbons while 27% of the C-C bond involves at least one alkyl carbon. The results indicate that the average carbon in this coal has 0.91 nearest carbon neighbors at a bond distance of 1.39 Å and 0.33 carbon neighbors at distance of 1.54 Å. The positions of ð and ã-bands are observed at a d-value of 3.37 Å and 4.92 Å respectively.