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本文应用TFD方法计算了电子的密度分布,应用维里定律计算了压力,指出固体中原子边界上对一个电子所受的位能不应该是零,严格推导证明,此值约接近于-e2/r0,相当于电子的自能。考虑这一项后,计算出的压力值比以前大大改善,特别是低压部分明显下降。根据这一考虑,本文计算了U,Pb,Au,Ag,Cu,Fe,Al,K,Na,Li等元素压缩度从1到10的冷压状态方程。所得结果,其高压部分和一般的TFD给出的接近;低压部分与实测值符合较好。如对U和Ag,其理论值与实测值相当一致,得到了P(v0)≈0的理想结果。对低Z元素,能带理论与TF模型有较大差别,这个差别主要是由于周期场对靠近边界的电子的作用引起的,把这个作用称为赝势。由于赝势的引入,计算结果十分理想,与实测值的误差均在10%左右。在数值计算方法上也作了改进,由于采用了新的变量替换,变换后的TFD方程所具有的两个边界条件在数值积分中很容易满足,其计算精度比以往提高三个量级。It was pointed out that the potential acting on an election at the boundary of an atom inside a solid should not vanish in a TF model of calculation. A strict deduction shows that it approaches to the value -e2/r0. When this term is taken into account, the calculated pressure values lie near those measured in a large range of compressions-Thus, equations of states for the metals U, Pb, Au, Ag, Cu, Fe, K, Al, Na and Li can be derived for the compression ratios from 1 to 10 at the temperature of absolute zero. Results are in good agreement with the corresponding current calculations in the high pressure limit. In the low pressure range, the agreement between calculated and observed ones are good within 10%. Particularly, for high-Z atomic number, for instance, the elements U and Ag, the agreement is excellent and at v=v0, P(v0)=0.Nevertheless, large deviations arise in the low-Z elements. This is due to the quantum effects of the Brillouin zones. As a recipe, normally a pseudo-potential is introduced. Accordingly, we do the same for the potential near the boundary of the atom-This leads to a better agreement within 10% again for all the elements mentioned above.In this paper, the method of numerical iteration for fitting the boundary conditions is improved by means of a new transformation of parameters. The accuracy in the numerical computation is thereby raised to 10-8.
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