Vinita Prajapati, Rekha Pyasi and P.L. Verma
We had examined the performances of numerous DFT (Density Functional Theory) functional intended for the computation of EPR a special factor of hyperfine coupling constants for several 3d transition metal complexes namely [Cu(CO)3], [Ni(CO)3H] and [Mn(CO)5]. For this, BHPW91, B3LYP, B3PW91, and BPW91 functional were used and the outcome received was compared with their respective experimental values. The obtained values of Hyperfine coupling constant from different DFT were seen in the sequence of BPW91>B3LYP>B3PW91>EXP, for [Cu(CO)3], BHPW91>B3PW91>BPW91>B3LYP>EXP, for [Mn(CO)5], and BHPW91>B3PW91>B3LYP>BPW91>EXP for [Ni(CO) 3H] complex.
On the basis of our studies, we have concluded that even though the outcome received by some of the DFT functional shows similar values from various performed experiments. Still the performances of the dissimilar functional for dissimilar transition metal complexes were not found identical. The performances of the functional BHPW91 were found more superior for [Cu(CO)3], BPW91 for [Ni(CO)3H] and B3LYP for [Mn(CO)5] metal complexes.
Keywords: Density Functional Theory, Transition Metal Complexes, Hyperfine coupling, performances, Experimental values, etc.