LINEAR-RESPONSE CALCULATION OF THE ELECTRON-PHONON COUPLING IN DOPED CACUO2

Using density-functional linear-response theory, we calculate the elec tron-phonon interaction for s- and d-wave pairing in the 0.24 hole dop ed infinite-layer compound CaCuO2. We find lambda(x2-y2) similar to 0. 3 to be positive and only slightly smaller than lambda(s) similar to 0 .4. This suggests that the electron-phonon mechanism alone is insuffic ient to explain the high T-c but could enhance another d-wave pairing mechanism. Results of calculated lattice dynamics and transport proper ties are also presented and discussed. Out-of-plane distortions are fo und essential for the stability.