Validation study of meta-GGA functionals and of a model exchange–correlation potential in density functional calculations of EPR parameters

2002 ◽  
Vol 4 (22) ◽  
pp. 5467-5474 ◽  
Author(s):  
Alexei V. Arbuznikov ◽  
Martin Kaupp ◽  
Vladimir G. Malkin ◽  
Roman Reviakine ◽  
Olga L. Malkina
2018 ◽  
Vol 96 (10) ◽  
pp. 934-938
Author(s):  
Delano P. Chong

The dipole polarizabilities (α) and polarizability anisotropies (Δα) of over 20 molecules are calculated to search for negative Δα. The geometry of each molecule is first optimized at the level of CCSD(T)/cc-pVQZ. Then, the α tensors are computed both with CCSD(T)/daug-cc-pVTZ in Gaussian 09 and with the exchange-correlation potential Vxc known as SAOP in the Amsterdam density functional theory program called ADF and a large basis set called QZ3P-3DIFFUSE. In addition to the popular formula of the ΔαRaman connected with Raman spectroscopy, we also present values of an alternative definition of the polarizability anisotropy ΔαKerr connected with Kerr spectroscopy, recently proposed by Kampfrath and colleagues (2018. Chem. Phys. Lett. 692: 319). On one hand, the signs of many ΔαRaman are undetermined; on the other hand, we obtain negative ΔαKerr for more than one-half of the small molecules studied. Of the 24 molecules studied, 18 have negative ΔαKerr.


2010 ◽  
Vol 09 (06) ◽  
pp. 619-622
Author(s):  
BOTHINA A. HAMAD

In this work, a theoretical study of the structural, electronic and magnetic properties are presented for Mn 0.5 Ni 0.5 alloyed overlayer adsorbed on Cu (001) surface. The calculations were performed using the density functional theory (DFT) and the exchange-correlation potential was treated by the generalized gradient approximation (GGA). The system was fully relaxed except for the central layer, which yields to outward relaxations and inward Mn and Ni surface atoms, respectively in the ferromagnetic and antiferromagnetic configurations. The in-plane ferromagnetic configuration was found to be more stable than the antiferromagnetic one by 25 meV/atom. The local magnetic moments of Mn atoms were found to be about 4 μ B , whereas those of the Ni atoms where found to be 0.46 μ B .


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