Three-dimensional crystal structure of novel aluminophosphate PST-5 solved using a powder charge flipping method

Abstract

The crystal structure of the novel aluminophosphate PST-5, an as-made form of PST-6, has been determined through X-ray powder diffraction using a framework search combined with a powder charge flipping method where the partially correct structure solution obtained using the powder charge flipping method was employed for the determination of the framework through Fourier recycling in the Focus suite of programs. The result of Rietveld refinement using the initial framework structure for novel aluminophosphate PST-5, synthesized hydrothermally using low-cost diethylamine as the organic structure-directing agent, suggested a three-dimensional pore structure containing interconnected ten and eight-membered rings. PST-5 has an orthorhombic Pmmn structure in which nine T atoms exist; the lattice parameters are a = 10.28 angstrom, b = 6.64 angstrom and c =10.89 angstrom, and the unit cell volume is roughly half that of PST-6.