model chemistry;
CBS-4M theory;
thermochemistry;
sulfur compounds;
ab initio molecular orbital methods;
D O I:
10.1007/s002140100274
中图分类号:
O64 [物理化学(理论化学)、化学物理学];
学科分类号:
070304 ;
081704 ;
摘要:
In order to calculate more accurately the enthalpies of formation, DeltaH(t)(o)(298 K), for large molecules using the CBS-4M method, a new formulation of the empirical higher-level correction to the energy is proposed: posed: DeltaE = a\S\I-2(ii)ii + b(n(alpha) + n(beta)) + c Delta [S-2] + Sigman(i)d(i). The new methodology (CBS-4MB) applied to a set of 114 molecules of different size significantly decreases the mean absolute deviation from 3.78 to 2.06 kcal/mol.