Solved by AlphaBetaGamma96 in post #3 
              
              
                Hi @KFrank, 
Here’s an example, 
>>> import torch
>>> 
>>> A = torch.randn(3,3)
>>> M = A@A.transpose(-2,-1)
>>> 
>>> M
tensor([[ 1.6559, -0.9484,  0.6780],
        [-0.9484,  1.2809, -0.0119],
        [ 0.6780, -0.0119,  0.5705]])
>>> torch.cholesky_inverse(M)
tensor([[ 1.0665,  0.3376, -1.2417],
 …