Electron-correlation-induced band renormalization and Mott transition in Ca_1-xSr_xVO₃

We present the local density approximate+Gutzwiller results for the electronic structure of Ca_1-xSr_xVO₃. The substitution of Sr²⁺ by Ca²⁺ reduces the bandwidth, as the V—O—V bond angle decreases from 180° for SrVO₃ to about 160° for CaVO₃. However, we find that the bandwidth decrease induced by the V—O—V bond angle decrease is smaller as compared to that induced by electron correlation. In correlated electron systems, such as Ca_1-xSr_xVO₃, the correlation effect of 3d electrons plays a leading role in determining the bandwidth. The electron correlation effect and crystal field splitting collaboratively determine whether the compounds will be in a metal state or in a Mott-insulator phase.