The matrices I would be working with are in the order of 6x6. Using the LinearSolve.KrylovJL_CG() seems to be causing numerical instability at the later stages of the DIIS solver for Coupled Cluster Equations I am trying to implement. The matrices I am trying to work with have small values of entries like
6×6 Symmetric{Float64, Matrix{Float64}}:
1.72458e-16 1.06023e-16 1.01555e-16 9.45545e-17 8.19558e-17 7.61703e-17
1.06023e-16 8.87195e-17 8.45981e-17 7.75149e-17 6.32949e-17 5.68955e-17
1.01555e-16 8.45981e-17 8.3458e-17 7.63146e-17 6.20451e-17 5.55372e-17
9.45545e-17 7.75149e-17 7.63146e-17 7.54038e-17 5.98022e-17 5.33082e-17
8.19558e-17 6.32949e-17 6.20451e-17 5.98022e-17 5.52861e-17 4.88773e-17
7.61703e-17 5.68955e-17 5.55372e-17 5.33082e-17 4.88773e-17 4.73348e-17
As of now I have not provided the exact code where the LinearSolve is used, but would be happy to provide if necessary.