Structure, hydrogen bonding and thermal expansion of ammonium carbonate monohydrate

Figure 3 from

Fortes, A. D., I. G. Wood, D. Alfé, E. R. Hernàndez, M. J. Gutmann, & H. A. Sparkes (2014): Structure, hydrogen bonding and thermal expansion of ammonium carbonate monohydrate Acta Crystallographica B 70(6), 948-962 (doi:10.1107/S205252061402126X)

 

(a) Slice through Fobs, a Fourier map computed from the observed structure factors phased on the refined atomic coordinates. The slice shows the nuclear scattering density in the a-c plane at b = 0.75; positive maxima correspond with C, N and O atoms, whereas negative minima correspond with H atoms. A drawing of the structure in this plane is shown in Fig 5.

(b) Electron density in the same plane as Figure 3(a) calculated by VASP at zero pressure and temperature. 2D visualizations created using VESTA (Momma & Izumi, 2011).