Abstract：Quantum chemistry ab initio calculation was applied to study the hyperfine structure of binary sodium phosphates. A series of phosphate model clusters were designed to simulate the microstructure of phosphates with different components. Closed-shell Hatree-Fock method (RHF) and the basis sets of 6-31G (d, p) were employed to optimize structures and calculate Raman frequencies of these phosphate model clusters. SIT (stress index of tetrahedron), which was well used in the study of silicate microstructures, had been adjusted before it was introduced to describe the microstructure of binary sodium phosphates. It was suggested that SIT of phosphates has good relationship with the Raman shift of the corresponding structures, which means SIT could also be used to study the hyperfine structure of binary sodium phosphates. Raman spectra of both solid and molten Na5P3O10 were determined in the range of room temperature to 1 473 K. A phase transition between 873 and 1 073 K was observed, and the main peaks of Na5P3O10 shifted to a lower frequency with increasing temperature. The microstructure units of Na5P3O10 crystal are the types of Q21 and Q112 with a ratio of 2∶1. With the increase in the temperature, various new microstructure units including Q0, Q11, Q21, Q112, Q122andQ222 appeared while Na5P3O10 was heated above the melting point, which led to the broadening and asymmetry of Raman spectra of molten Na5P3O10. It came to an understanding that the microstructure units of phosphates may change at different temperature, especially above the melting points. The introduction of SIT and hyperfine structure could help analyze the Raman spectra of phosphates both qualitatively and quantitatively.
Key words：Phosphorus-oxygen tetrahedron;Melt;Quantum chemistry ab initio;Stress Index of Tetrahedron
[1] ZHENG Dian-mo(郑典模). Chemical Engineer(化学工程师)，1998，(1): 34. [2] Remy Corrine, Reynard Bruno, Madon Michel. Journal of the American Ceramic Society，1997, 80(2): 413. [3] JIANG Guo-chang, YOU Jing-lin, YU Bing-kun, et al(蒋国昌, 尤静林，余丙鲲，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2000, 20(2): 206. [4] McMillan P F, Gillet H, Reynard B. Geochimica et Cosmochimica Acta, 1994, 58(17): 3653. [5] Yu K. Growth of Crystals，1991, 16(8): 199. [6] Tatsumisago M, Kowada Y, Minami T. Physics and Chemistry of Glasses，1988, 29(2): 63. [7] Liebau F. Structure and Bonding in Crystals II. M O’keefe A N, New York: Academic Press, 1981. 197. [8] Brow R K, Kirkpatrick R J, Turner G L. Journal of Non-Crystalline Solids，1990, 116(1): 39. [9] Brow R K. Journal of Non-Crystalline Solids，2000, 263: 1. [10] GUO Ying-feng, YOU Jing-lin, JIANG Guo-chang, et al(郭迎峰, 尤静林, 蒋国昌, 等). Spectroscopy and Spectral Analysis(光谱学与光谱分析)，2003, 23(5): 855. [11] Van Wazer J R. Phosphate and its Compounds. New York: Interscience, 1958. [12] Uchino T, Ogata Y. Journal of Non-Crystalline Solids, 1995, 181(1-2): 175. [13] Uchino T, Ogata Y. Journal of Non-Crystalline Solids, 1995, 191(1-2): 56. [14] Uchino T, Yoko T. Journal of Non-Crystalline Solids, 2000, 263: 180. [15] YOU Jing-lin, JIANG Guo-chang, HOU Huai-yu, et al. Journal of Raman Spectroscopy，2005, 36: 237. [16] Cruickshank D W J. Acta Crystallographica，1964, 17(6): 677. [17] Macgillavry C H, Dedecker H C J, Nijland L M. Nature，1949, 164: 448. [18] Tarasov V V. New Problems of Physics of Glasses. Moscow: Gosstroizdat, 1959. [19] De Decker H C J. Recueil des Travaux Chimiques des Pays-Bas et de la Belgique，1941, 60: 413. [20] Arbib E H, Elouadi B, Chaminade J P, et al. Journal of Solid State Chemistry，1996, 127(2): 350. [21] Stachel D, Svoboda I, Fuess H. Acta Crystallographica, Section C: Crystal Structure Communications，1995, 51(6): 1049. [22] Lissel E, Jansen M, Jansen E, et al. Eitschrift Fuer Kristallographie，1990, 192: 233. [23] Ondik H M. Acta Crystallographica，1965, 18(2): 226. [24] Jost K H. Acta Crystallographica，1961, 14(8): 844. [25] Davies D R, Corbridge D E C. Acta Crystallographica，1958, 11(5): 315. [26] Leung K Y, Calvo C. Canadian Journal of Chemistry，1972, 50(16): 2519. [27] Gilliam Sean J, Kirkby Scott J, Merrow Clifton N, et al. Journal of Physical Chemistry B，2003, 107(13): 2892. [28] Ir Beattie, Livingston Kms, Ozin G A. Journal of American Chemical Society，1970, (3): 449.
