Deposit Items for Volume 82, No. 1-2, January-February, 1997


David C. Palmer, Martin T. Dove, Richard M. Ibberson, and Brian M. Powell
Structural behavior, crystal chemistry, and phase transitions in substituted leucite: High-resolution neutron powder diffraction studies   16

Item #AM-97-633

Tables 3,10-40
Palmer_p16_97_T.txt text document (36 K)

Quicktime Movie of transition, 111 View
Palmer_p16_97_111.qt Quicktime Movie (1 MB)

Quicktime Movie of transition, 001 View
Palmer_p16_97_001.qt Quicktime Movie (1 MB)

Crystal Structure Refinements

Quality of Refinements

The quality of refinements can be assessed using a number of quantities:

where N is the number of data points, P is the number of variables, y is the intensity at any point in the scan, and a is the corresponding error. We found that most of our refinements were nearly as good as physically possible (chi squared ~ 1), so that the final weighted R factor, Rw, is close to the expected R factor, Rexp, implying that there are no significant unaccounted systematic errors in the data.

Origin Offset

The intermediate tetragonal phase (I41/acd) and the cubic phase (Ia3d) were refined using nonconventional unit-cell settings. In both cases, the origin was offset by a/2, relative to the standard, International Tables setting. This was so that the unit cells of all three phases would match.


Paola Comodi and Pier Francesco Zanazzi
The pressure behavior of clinozoisite and zoisite: An X-ray diffraction study    61

Item #AM-97-631

Table 3. Observed and Calculated Structure Factors
Table 3 is not available online. Please contact the Business Office.


Hiroyuki Horiuchi, Akihiro Saito, Toshinaga Tachi, and Hiroshi Nagasawa
Structure of synthetic Li2(Mg,Cu)Cu2[Si2O6]2: A unique chain silicate related to pyroxene   143

Item #AM-97-632

Table 4 Observed and Calculated Structure Factors
Horiuchi_p143_97_T4.txt text document (56 K)


Biswajit Mukhopadhyay, M.J. Holdaway, and Andrea M. Koziol
A statistical model of thermodynamic mixing properties of Ca-Mg-Fe2+ garnets   165

Item #AM-97-630

Table 1a. Data sets and robust weights for regressions.
Mukhopadhyay_p165_97_T1a.doc Microsoft Word Document (52 K)

Table 1b. Regression results on data from Table 1A
Mukhopadhyay_p165_97_T1b.doc Microsoft Word Document (52 K)

Table 1c. Procedure for optimizing delta G adjustment conducted on smoothed data and unsmoothed data using OMLR on garnet-orthopyroxene data at 1100 °C, 50 kbar, 24 points, Kawasaki and Matsui (1983).
Mukhopadhyay_p165_97_T1c.doc Microsoft Word Document (28 K)


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