Oscillator strengths, first-order properties, and nuclear gradients for local ADC(2)

摘要: We describe theory and implementation of oscillator strengths, orbital-relaxed first-order properties, nuclear gradients for the local algebraic diagrammatic construction scheme through second order. The formalism is derived via time-dependent linear response based on a second-order unitary coupled cluster model. presented here modification our previously developed algorithms Laplace transform (CC2LR); approximations thus are state specific adaptive. symmetry Jacobian leads to considerable simplifications relative CC2LR method; as result, gradient evaluation about four times less expensive. Test calculations show that in geometry optimizations, usually very similar geometries obtained with method (provided applicable). As an exemplary application, we performed optimizations low-lying singlet states chlorophyllide a.