An ab initio study of the equilibrium geometries and vibrational frequencies of the group IIa difluorides MF2 (M=Be, Mg, Ca)

✍ Scribed by John M. Dyke; Timothy G. Wright

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 622 KB
• Volume: 169
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(90)85178-f

✦ Synopsis

Ab initio molecular orbital calculations have been performed on the ground electronic states of BeF*, MgFz and CaF,. Minimum energy geometries and vibrational frequencies were calculated at the Hartree-Fock (HF) level using analytical derivative methods. Some account was taken of electron correlation by performing the geometry optimizations at the Msller-Plesset secondorder (MP2) level; vibrational frequencies were also calculated at this level. BeF2 and MgFz were found to have linear, Dmh equilibrium geometries, whereas CaF* was found to have a Czv geometry, with a bond angle of 152". A single-point configuration interaction calculation including single and double excitations (CISD) was performed at the MP2 optimized geometry to gain some insight into the factors which determine the equilibrium geometry of CaF,.