General

The cubic scaling GW method is implemented in exciting following the approach described by Kutepov et al[@kutepov2017linearized]. A key distinction between Kutepov’s methodology and ours lies in their utilization of Matsubara frequencies, whereas we employ the zero-temperature approach relying on imaginary time.

Benchmark

Color plot of polarizability matrix in MT-MT case. The left panel shows the cubic-scaling polarizability and right panel shows the difference between the cubic and quartic polarizability matrix.