Amorphous GeSe2 Under Pressure

Hap corresponds to the partial coordination number obtained by integrating the corresponding PCF first peak up to the first minimum. Results for previous simulations at from [26] and experiment from [88] compared to new simulation at and at the relaxed structure p  

Not only the simulation at the experimental density provide a better agreement with the measurements than the old p one, but also the different coordination numbers as obtained from p simulation feature provides an unprecedented improvement. 

The three main peaks in the gcece refers as r increases to Ge atoms involved in homopolar bonds, edge-sharing and corner-sharing connection respectively. The following table present the different Ge environment fractions as obtained from direct analysis  

The current results within the relaxed model (p ) shows a very good reproduction of the experimental fraction of Ge atoms involved in homopolar bonds. The fraction of corner sharing Ge atoms is improved upon previous simulation, this stems from the substantial change of the shape of the third goece peak. 

Note that in [89], a molecular dynamics approach was used in conjunction with a reverse Monte Carlo method 

---

Experimentally, the crystallization and the amorphization of binary amorphous systems under pressure have already been the subjects of many studies [73-81]. In 1965, Prewitt and Young [73] found two new crystalline phases of Germanium and Silicium disulfides at T=300 K under pressure. Later, Shimada and Dachille [74] studied the crystallization of amorphous GeSe2 under pressure and found that three different crystalline phases exist depending on temperature and pressure. They also quoted that the crystallization was inhibited for temperatures lower than T=573 K. 

---