Evidence for possible electronic contributions to the W(001) surface phase transition

The calculated surface generalized susceptibility, determined from ab initio self-consistent thin-film energy bands for the unreconstructed phase of W(001), displays a prominent peak at M̄ when matrix elements and local-field corrections are included and supports proposed charge-density-wave interpretations of the observed reconstruction to the c(2×2) phase. These results are consistent with the Debe and King parallel-shift model and the suggestion that W(001)c(2×2)-H at room temperature represents an impurity-stabilized substrate reconstruction.