Polarizability pseudospectra and dispersion coefficients for H(1s)-H(1s)

Pseudostate decomposition of the first five multipole static polarizabilities of H(1s) obtained from a Givens-Householder diagonalization of (H 0 - EE 0 ) over a N-term STO basis with orbital exponent c = 1 allows for a rapidly convergent evaluation of c 2n dispersion coefficients for H(1s)-H(1s). Twenty-five term pseudospectra with exact ψ 0 give C 2n values that are accurate to at least 16 significant figures up to 2 n = 14.