One of the software I know is able to search/generate new structures is USPEX.
From their site, USPEX means:
USPEX (Universal Structure Predictor: Evolutionary Xtallography...and
in Russian "uspekh" means "success" - owing to the high success rate
and many useful results produced by this method) is a method developed
by the Oganov laboratory since 2004. The problem of crystal structure
prediction is very old and does, in fact, constitute the central
problem of theoretical crystal chemistry. In 1988 John Maddox wrote
"One of the continuing scandals in the physical sciences is that
it remains in general impossible to predict the structure of even
the simplest crystalline solids from a knowledge of their chemical
composition solids such as crystalline water (ice) are still
thought to lie beyond mortals' ken".
USPEX code solves this problem and allows to predict crystal structure
with arbitrary P-T conditions by knowing only chemical composition of
the material. Nowdays, it is used by over 7600 researchers worldwide.
The First Blind Test of Inorganic Crystal Structure Prediction shows
that USPEX outperforms other methods in terms of efficiency and
reliability. The method continues to be rapidly developed.
It is developed in Python but needs other codes to optimize/characterize the generated structures. Works with VASP, GULP, LAMMPS, QuantumEspresso and ABINIT and run in any Linux based system.