Abstract: Systematic studies were made on graph theory in quantitative structure-activity/property relationships(QSAR/QSPR). Here Quantitative Molecular Modelling (QMM) was done on quantitative structure-spec trum relationship (QSSR) studies. The regularity of chemical shift (CSC) for carbon-13 nuclear magnetic resona nce (¹³C NMR) in 70 Haloalkanes was modelled and/or predicted by using a set of novel chemical graph indices, called molecular topological subgraph index vector (VSG), the newly developed SGI descriptors with R > 0.95 as an equation of multiple variables:
CSC=∑_q=1^Qb_qg_q=b^*X=44.124+30.216X₁+11.672X₂-14.591X₃-72.819X₄ N=45,R=0.9741,SD=22.7612,F=185.6123,U=384642.0000,Q=20722.875 where q=1 to 4 (F,Cl,Br,I), with good results.

Key words: Quantitative structure activity/property/spectrum relationships (QSAR/QSPR/QSSR).Quantitative Molecular Modelling (QMM), Chemical shift sum (CSS), Carbon-13 nuclear magnetic resonance (¹³C NMR), Haloalkanes, Novel chemical graph indices, Integrated molecular topological subgraphv ector (VMSG,g)