钒酸铋第一性原理计算收敛性测试

Convergence Test of First-Principles Calculation of Bismuth Vanadate

对正交相钒酸铋进行第一性原理计算收敛性测试,考察了截断能和K点不同对计算终能、总耗机时和内存占用峰值的影响。结果发现,当固定K点(5×5×2)时,随着截断能的增加,计算终能先急剧降低后缓慢降低,总耗机时表现出起伏变化的特点,内存占用峰值近似地表现为线性增加;当固定截断能为660 eV,改变K点(m×m×n)时,以相同的n为一组,各组计算终能随K点的变化均表现出凹型变化特点,n=3和n=4的总耗机时、内存占用峰值变化基本相似,n=1和n=2的总耗机时、内存占用峰值变化也有一定的相似性。

The convergence test of first principles calculation of orthorhombic BiVO4 was carried out.The effect of truncation energy and K point on the calculated final energy,the total machine time and the occupied memory peak value was investigated.The results show that when K point(5×5×2)is fixed,with the increase of truncation energy,the calculated final energy decreases sharply at first and then slowly,the total machine time shows a certain fluctuation,and the occupied memory peak increases approximately linearly.When the cutoff energy is fixed(660 eV)with changing K point(m×m×n)and taking the same n as a group,the calculated final energy of each group shows concave changes with K point.The changes of total machine time and occupied memory peak of n=3 and n=4 are basically similar,and those of n=1 and n=2 are also similar in most degree.