Geometries and Electronic Structures of W_4 and W_4~- Clusters

摘要

Geometries and electronic structures of W_4 and W_4 clusters were studied by use of density functional methods B3LYP,B3P86,B3PW91,BHLYP,BLYP,and MPW1PW91.The calculated results indicate that the three-dimensional structure of singlet state with either D_(2d) symmetry(B3LYP,B3P86,B3PW91,BLYP,and MPW1PW91) or C_(2v) symmetry(BHLYP) is the ground state for the W_4 cluster.For the W_4~- cluster,the doublet state is preferred,and the most stable structure is also 3D with either D_(2d) symmetry(B3LYP,B3PW91,BHLYP,BLYP) or C_(2v) symmetry(B3P86 and MPW1PW91).The calculated electron affinity at B3P86 gives the best performance compared with experiment.For the dissociation channel,W + W_3 is suggested to be the possible route for the W_4 cluster.For the W_4~- cluster,W + W_3~- is the most likely route for dissociation,in agreement with experiment.