Pascale F, Catti M, Damin A, Orlando R, Saunders V R, Dovesi R
Laboratoire de Cristallographie et Modélisation des Matériaux Minéraux et Biologiques, Université Henri Poincaré, BP 239, 54506 Vandaeuvre les Nancy Cedex 05, France.
J Phys Chem B. 2005 Oct 6;109(39):18522-7. doi: 10.1021/jp052991e.
The vibrational spectrum of Ca3Fe2Si3O12 andradite is calculated at the Gamma point by using the periodic ab initio CRYSTAL program that adopts an all-electron Gaussian-type basis set and the B3LYP Hamiltonian. The full set of frequencies (17 IR active, 25 Raman active, and 55 inactive modes) is calculated. The effect of the basis set on the calculated frequencies is discussed. The modes are characterized by direct inspection of the eigenvectors and isotopic substitution. The present calculations permit us to clarify some of the assignment problems raised by experiments. The mean absolute differences of the various modes with respect to the available experimental IR and Raman data are as small as 9 and 5 cm(-1), respectively.
利用采用全电子高斯型基组和B3LYP哈密顿量的周期性从头算CRYSTAL程序，在Γ点计算了钙铁榴石Ca3Fe2Si3O12的振动光谱。计算了全套频率（17个红外活性模式、25个拉曼活性模式和55个非活性模式）。讨论了基组对计算频率的影响。通过直接检查本征向量和同位素取代来表征这些模式。目前的计算使我们能够澄清一些实验提出的归属问题。各种模式相对于现有实验红外和拉曼数据的平均绝对差分别小至9和5 cm-1。
