Pressure Tuning of the Charge Density Wave in the Halogen-Bridged   Transition-Metal (MX) Solid $Pt_2Br_6(NH_3)_4$
  We report the pressure dependence up to 95 kbar of Raman active stretching modes in the quasi-one-dimensional MX chain solid $Pt_2Br_6(NH_3)_4$. The data indicate that a predicted pressure-induced insulator-to-metal transition does not occur, but are consistent with the solid undergoing either a three-dimensional structural distortion, or a transition from a charge-density wave to another broken-symmetry ground state. We show that such a transition cacan be well-modeled within a Peierls-Hubbard Hamiltonian. 1993 PACS: 71.30.+h, 71.45.Lr, 75.30.Fv, 78.30.-j, 81.40.Vw 
G.S. Kanner, J.Tinka Gammel, S.P. Love, S.R. Johnson, B. Scott, and   B.I. Swanson (Los Alamos National Laboratory, Los Alam...