TY - JOUR

T1 - Modification of the GAUSSIAN-2 theoretical model

T2 - The use of coupled-cluster energies, density-functional geometries, and frequencies

AU - Mebel, A. M.

AU - Morokuma, K.

AU - Lin, Ming-Chang

PY - 1995/1/1

Y1 - 1995/1/1

N2 - A family of modified GAUSSIAN-2 (G2M) calculational schemes have been proposed, based on geometry optimization and vibrational frequency calculations using the hybrid density-functional approach, and electron correlation evaluation using the coupled-cluster methods. The most accurate model, called G2M(RCC), gives the average absolute deviation of calculated atomization energies from experiment for 32 first-row compounds of 0.88 kcal/mol. The other two methods, called G2M(RCC,MP2) and G2M(rcc,MP2), exhibit the average absolute deviations of 1.15 and 1.28 kcal/mol, respectively, and can be used for the calculations of molecules and radicals of larger sizes containing up to six to seven heavy atoms. The G2M(rcc,MP2) model demonstrates an accuracy comparable to that of G2(MP2) and requires less intensive computations than the latter. The preference of the G2M(RCC) methods over the original G2 is expected to be particularly significant for the open shell systems with large spin contamination.

AB - A family of modified GAUSSIAN-2 (G2M) calculational schemes have been proposed, based on geometry optimization and vibrational frequency calculations using the hybrid density-functional approach, and electron correlation evaluation using the coupled-cluster methods. The most accurate model, called G2M(RCC), gives the average absolute deviation of calculated atomization energies from experiment for 32 first-row compounds of 0.88 kcal/mol. The other two methods, called G2M(RCC,MP2) and G2M(rcc,MP2), exhibit the average absolute deviations of 1.15 and 1.28 kcal/mol, respectively, and can be used for the calculations of molecules and radicals of larger sizes containing up to six to seven heavy atoms. The G2M(rcc,MP2) model demonstrates an accuracy comparable to that of G2(MP2) and requires less intensive computations than the latter. The preference of the G2M(RCC) methods over the original G2 is expected to be particularly significant for the open shell systems with large spin contamination.

UR - http://www.scopus.com/inward/record.url?scp=36449008175&partnerID=8YFLogxK

U2 - 10.1063/1.470313

DO - 10.1063/1.470313

M3 - Article

AN - SCOPUS:36449008175

SN - 0021-9606

VL - 103

SP - 7414

EP - 7421

JO - The Journal of Chemical Physics

JF - The Journal of Chemical Physics

IS - 17

ER -