Correction apparatus, system, method, and program

A system comprising:

• an X-ray diffractometer comprising an X-ray generator that generates X-rays, a detector that detects the X-rays, and a goniometer;
• and
• a correction apparatus for correcting a structure factor, the correction apparatus including processing circuitry configured to
• acquire the structure factor calculated based on a total scattering data measured by the X-ray diffractometer;
• calculate PDF (Pair Distribution Function) from the acquired structure factor;
• calculate a first correction function and a second correction function, the first correction function includes a product of the PDF data and a cut-off function and is a function Fourier-transformed within a predetermined range, and the second correction function includes a product of a variable representing the distance of the PDF and the cut-off function and is a function Fourier-transformed within the predetermined range, the cut-off function is a function that cuts off the long distance data of the PDF data, with the range equal to or greater than a constant determined based on the first peak position first of the PDF as the long distance side;
• calculate density based on the first correction function and the second correction function;
• calculate a correction amount comprising the first correction function, the second correction function, and the density;
• correct the structure factor using the correction amount, the correction of the structure factor is performed by adding or subtracting the amount of correction to the structure factor before correction and calculating the structure factor after correction;
• and
• calculate an R-factor value indicating correction accuracy, the R-factor value comprising the first correction function and the second correction function.

A method for correcting a structure factor, the method comprising:

• acquiring the structure factor calculated based on a total scattering data measured by an X-ray diffractometer;
• calculating PDF (Pair Distribution Function) from the acquired structure factor;
• calculating a first correction function, and a second correction function, the first correction function includes a product of the PDF data and a cut-off function and is a function Fourier-transformed within a predetermined range, and the second correction function includes a product of a variable representing the distance of the PDF and the cut-off function and is a function Fourier-transformed within the predetermined range, the cut-off function is a function that cuts off the long distance data of the PDF data, with the range equal to or greater than a constant determined based on the first peak position r1st of the PDF as the long distance side;
• calculating density based on the first correction function and the second correction function;
• calculating a correction amount comprising the first correction function, the second correction function, and the density, the correction amount includes a difference between a product of the second correction function and the calculated density and the first correction function;
• correcting the structure factor using the correction amount, the correction of the structure factor is performed by adding or subtracting the amount of correction to the structure factor before correction and calculating the structure factor after correction;
• and
• calculating an R-factor value indicating correction accuracy, the R-factor value comprising the first correction function and the second correction function.

A non-transitory computer-readable storage medium storing computer-readable instructions thereon which, when executed by a computer, cause the computer to perform a method, the method comprising:

• acquiring the structure factor calculated based on a total scattering data measured by an X-ray diffractometer;
• calculating PDF (Pair Distribution Function) from the acquired structure factor;
• calculating a first correction function, and a second correction function, the first correction function includes a product of the PDF data and a cut-off function and is a function Fourier-transformed within a predetermined range, and the second correction function includes a product of a variable representing the distance of the PDF and the cut-off function and is a function Fourier-transformed within the predetermined range, the cut-off function is a function that cuts off the long distance data of the PDF data, with the range equal to or greater than a constant determined based on the first peak position first of the PDF as the long distance side;
• calculating density based on the first correction function and the second correction function;
• calculating a correction amount comprising the first correction function, the second correction function, and the density, the correction amount includes a difference between a product of the second correction function and the calculated density and the first correction function;
• correcting the structure factor using the correction amount, the correction of the structure factor is performed by adding or subtracting the amount of correction to the structure factor before correction and calculating the structure factor after correction;
• and
• calculating an R-factor value indicating correction accuracy, the R-factor value comprising the first correction function and the second correction function.