A new high-pressure polymorph of phosphoric acid

ABSTRACT: The high-pressure behaviour of monoclinic phosphoric acid is presented and a new high-pressure orthorhombic phase is reported. The molecule–molecule interaction energies of the orthorhombic phase are shown to be more attractive than those of the low-pressure monoclinic phase. The high-pressure structural behaviour of phosphoric acid is described. A compression study of the monoclinic phase, using neutron powder diffraction and X-ray single-crystal diffraction, shows that it converts to a previously unobserved orthorhombic phase on decompression. Compression of this new phase is reported up to 6.3 GPa. The orthorhombic phase is found to be more efficiently packed, with reduced void space, resulting in a larger bulk modulus. Molecule–molecule interaction energies reveal a more extensive netw

SUBMITTER: Bull C 

PROVIDER: S-EPMC5744408 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature