Youzhi Luo

@ycremar `pyscf` cannot be removed because it is required for evaluation in ggraph3d, but `post1` version requirement can be removed.

@akhilesh2295 I have updated the pyscf version to 1.7.6 in setup.py, could you please try git installation with new setup.py? Thanks!

@Takaogahara Thank you for pointing this bug! Actually ''for key in self.data.keys'' follows the implementaion of InMemoryDataset class in pyg 1.x, but pyg 2.x updates the implementation and I guess...