A computational investigation of 17O quadrupolar coupling parameters and structure in -quartz phase

First-principles investigation of the relation between structural and NMR parameters in vitreous GeO2

“…In figure 3, we plot C Q and η for 17 O against the local angle Ge-O-Ge. The 17 O quadrupole coupling constant C Q shows a linear correlation with the Ge-O-Ge bond angle, providing further support to the relationship which was previously suggested on the basis of cluster calculations for quartz GeO 2 [34,35]. For the asymmetry parameter η, we also find a clear correlation, showing a characteristic dependence which has also been observed for quartz GeO 2 [34,35] and crystalline SiO 2 systems [14].…”

Multinuclear NMR of CaSiO3 glass: simulation from first-principles

“…12,[15][16][17] Nevertheless, the spectra can be still difficult to interpret, since a deep knowledge of the correlations between the NMR parameters and local structure is required. This can be achieved either empirically by reference to materials of a known structure [18][19][20] or theoretically using ab initio calculations.…”

Effects of the degree of polymerization on the structure of sodium silicate and aluminosilicate glasses and melts: An 17O NMR study

“…Recent findings revealed by 17 O NMR also include the presence of NBOs on the charge-balanced join (CaO/Al 2 O 3 = 1) , bonding preference of Ca-O-Si over Ca-O-Al (Allwardt et al, 2003;Lee and Stebbins, 2006), the quantification of cation ordering around NBOs (Florian et al, 1996;Lee and Stebbins, 2003b;, a decrease in the NBO fraction in oxide glasses with pressure Lee, 2004), and an increase in the chemical disorder with temperature (Dubinsky and Stebbins, 2006;Stebbins et al, 2008). 17 O NMR parameters, including the isotropic chemical shift ( 17 O d iso ) and the quadrupolar coupling constant ( 17 O C q ), have been correlated with the local short-to-medium-range coordination environments around oxygen (Farnan et al, 1992;Vermillion et al, 1998;Lee et al, 2001;Clark et al, 2004;Lee, 2004;Clark and Grandinetti, 2005;Sefzik et al, 2007). For example, 17 O d iso exhibits an increasing trend with the Si-O bond length while 17 O C q is often positively correlated with the Si-O-Si bond angle (Farnan et al, 1992;Vermillion et al, 1998;Lee et al, 2001;Clark et al, 2004;Lee, 2004;Clark and Grandinetti, 2005;Sefzik et al, 2007), allowing us to estimate the changes in topology (bond angle and length) with the degree of polymerization.…”

“…17 O NMR parameters, including the isotropic chemical shift ( 17 O d iso ) and the quadrupolar coupling constant ( 17 O C q ), have been correlated with the local short-to-medium-range coordination environments around oxygen (Farnan et al, 1992;Vermillion et al, 1998;Lee et al, 2001;Clark et al, 2004;Lee, 2004;Clark and Grandinetti, 2005;Sefzik et al, 2007). For example, 17 O d iso exhibits an increasing trend with the Si-O bond length while 17 O C q is often positively correlated with the Si-O-Si bond angle (Farnan et al, 1992;Vermillion et al, 1998;Lee et al, 2001;Clark et al, 2004;Lee, 2004;Clark and Grandinetti, 2005;Sefzik et al, 2007), allowing us to estimate the changes in topology (bond angle and length) with the degree of polymerization.…”