Abstract Molecular dynamics simulation is employed to study the structural evolution of low density amorphous ice during its compression from one atmosphere to 2.5 GPa. Calculated results show that high density amorphous ice is formed at an intermediate pressure of $\sim $1.0 GPa; the O--O--O bond angle ranges from 83$^{\circ}$ to 113$^{\circ}$, and the O--H$\cdots$O bond is bent from 112$^{\circ}$ to 160$^{\circ}$. Very high density amorphous ice is obtained by quenching to 80 K and decompressing the ice to ambient pressure from 160 K/1.3 GPa or 160 K/1.7 GPa; and the next-nearest O--O length is found to be 0.310 nm, just 0.035 nm beyond the nearest O--O distance of 0.275 nm.
Received: 30 July 2007
Revised: 31 January 2008
Accepted manuscript online:
Altmetric calculates a score based on the online attention an article receives. Each coloured thread in the circle represents a different type of online attention. The number in the centre is the Altmetric score. Social media and mainstream news media are the main sources that calculate the score. Reference managers such as Mendeley are also tracked but do not contribute to the score. Older articles often score higher because they have had more time to get noticed. To account for this, Altmetric has included the context data for other articles of a similar age.
