Split .h5 file in two

I have a dataset of 15 GB in .h5 extension.
The dataset has following Keys:

Keys: <KeysViewHDF5 [‘train_ims’, ‘train_length’, ‘train_words’, ‘val_ims’, ‘val_length’, ‘val_words’]>

I want to break it in two .h5 files with same keys and equal sizes.

Is it possible? If yes, please help.