Since 1977 ab initio MO calculation has been undertaken in Peking University. Some works have been finished and published, for example, on the study of electronic structure of AIH4- anion (Scientia sinica, 24 （1981）...Since 1977 ab initio MO calculation has been undertaken in Peking University. Some works have been finished and published, for example, on the study of electronic structure of AIH4- anion (Scientia sinica, 24 （1981）, 956. We have also undertaken the optimization of basis sets. In this communication we are proposing improved STO-3G （new） and STO-4G （new） minimal basis sets, which exhibit considerable improvement over the STO-KG basis sets adopted usually. Using STO 3G （new）, we have obtained the total energies展开更多
With enriched antimony isotopes of 99.224 atom% ^(121)Sb and 99.528 atom% ^(123)Sb, twotracer solutions were prepared, whose antimony content was ascertained by the isotopicdilution analysis utilizing an accurately as...With enriched antimony isotopes of 99.224 atom% ^(121)Sb and 99.528 atom% ^(123)Sb, twotracer solutions were prepared, whose antimony content was ascertained by the isotopicdilution analysis utilizing an accurately assayed laboratory standard. Mass spectrometricmeasurements were made on a Finnigan MAT- 261 instrument to find the ratio of masses121 and 123. Five synthetic mixtures formed from the tracers served to determine thecorrection factor of mass discrimination. The isotopic abundances thus found for the anti-mony in the mineral stibnite together with the known nuclidic masses yield an accurateatomic weight of antimony as 121 .7575± 0 .0009.展开更多
Understanding the driving force for the formation of high-nuclearity clusters is still aformidable challenge. Recently, we have reported two crystal structures with the largestpolymetallate clusters involving mixed-va...Understanding the driving force for the formation of high-nuclearity clusters is still aformidable challenge. Recently, we have reported two crystal structures with the largestpolymetallate clusters involving mixed-valence molybdenum and vanadium （Ⅳ） or Fe （Ⅲ）, ofwhich the Mo; V and Mo; Fe ratios are 57:6. Here we report the crystal structure ofnew heteropolyanion involving mixed-valence molybdenum and Fe（Ⅱ）. [H<sub>8</sub>Mo<sub>57</sub>Fe<sub>6</sub><sup>Ⅱ</sup>O<sub>185</sub>（NO）<sub>6</sub>·（H<sub>2</sub>O）<sub>16</sub>（MoO）<sub>2</sub>]<sup>6-</sup>,of which the Mo:Fe ratio is as high as 59:6.展开更多
文摘Since 1977 ab initio MO calculation has been undertaken in Peking University. Some works have been finished and published, for example, on the study of electronic structure of AIH4- anion (Scientia sinica, 24 （1981）, 956. We have also undertaken the optimization of basis sets. In this communication we are proposing improved STO-3G （new） and STO-4G （new） minimal basis sets, which exhibit considerable improvement over the STO-KG basis sets adopted usually. Using STO 3G （new）, we have obtained the total energies
基金Project supported by the National Natural Science Foundation of China.
文摘With enriched antimony isotopes of 99.224 atom% ^(121)Sb and 99.528 atom% ^(123)Sb, twotracer solutions were prepared, whose antimony content was ascertained by the isotopicdilution analysis utilizing an accurately assayed laboratory standard. Mass spectrometricmeasurements were made on a Finnigan MAT- 261 instrument to find the ratio of masses121 and 123. Five synthetic mixtures formed from the tracers served to determine thecorrection factor of mass discrimination. The isotopic abundances thus found for the anti-mony in the mineral stibnite together with the known nuclidic masses yield an accurateatomic weight of antimony as 121 .7575± 0 .0009.
文摘Understanding the driving force for the formation of high-nuclearity clusters is still aformidable challenge. Recently, we have reported two crystal structures with the largestpolymetallate clusters involving mixed-valence molybdenum and vanadium （Ⅳ） or Fe （Ⅲ）, ofwhich the Mo; V and Mo; Fe ratios are 57:6. Here we report the crystal structure ofnew heteropolyanion involving mixed-valence molybdenum and Fe（Ⅱ）. [H<sub>8</sub>Mo<sub>57</sub>Fe<sub>6</sub><sup>Ⅱ</sup>O<sub>185</sub>（NO）<sub>6</sub>·（H<sub>2</sub>O）<sub>16</sub>（MoO）<sub>2</sub>]<sup>6-</sup>,of which the Mo:Fe ratio is as high as 59:6.
