Atoms volume expansion

The molecular volume at the ordinary temperature13 is 111 c.c., and the ratio of this value to the sum of the atomic volumes of the constituent elements14 is 1-21. From measurements of density and coefficient of expansion at -194° C. the molecular volume at 0° Abs. has been calculated15 to be 76-1. The molecular weight determined by... 

The volume expansion per gram atom of metal, A V, as used in this report, will be defined as ... 

Curve 1 is a plot of data from the investigation of Filbert (8) at —45° C. Filbert s results show a pronounced minimum in the volume expansion vs. concentration curve at 0.0AN. The AV value at the minimum is 30 cc./gram-atom as compared with the limiting value of approximately 42 cc./gram-atom at infinite dilution. 

X-ray diffraction measurements show that the ThMn12-type crystalline structure of TbFe6Co5Ti compound is retained upon hydrogenation. The introduction of hydrogen atoms increases the lattice constants. It leads to an isotropic volume expansion with the c/a ratio being almost unchanged. 

The atomic volumes and coefficients of expansion display a similar relationship. 

The mean-square fluctuation in atomic positions (MSF) and the coefficient of thermal volume expansion (a ), calculated using the fluctuation formula [39], are presented in Table 3. The former varies little over the different data blocks, and the standard deviation is less than 1% of the average, indicating that this property has also converged by 20 ps. 

R. STEPHEN BERRY, THOMAS L. BECK, HEIDI L. DAVIS, AND JULIUS JELLINEK the atomic volume in the bulk v, can be used to generate a similar expansion,... 

In 2002, Morrow and Maginn presented an all-atom force field for [C4mim][PF6] using a combination of DFT calculations (B3LYP/6-311+G ) and CHARMM 22 parameter values [13]. MD simulations were carried out in the isothermal-isobaric ensemble at three different temperatures. The calculated properties contained infrared frequencies, molar volumes, volume expansivities, isothermal compressibilities, self-diffusivities, cation-anion exchange rates, rotational dynamics, and radial distribution functions. These thermodynamic properties were found to be in good agreement with available experimental values [13]. 

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