Stephens Peakshapes for TOF NPD

jmas5

I've been working on some combined SXRD/NPD refinements with data from Diamond (I-11) and WISH (ISIS). I have always found the Stephens peakshape macros to be incredibly helpful for XRD, but have not been able to use these for my NPD. I believe the issue is due to the TOF (microsecond) data in NPD, as opposed to the 2theta data in XRD, as the macro calls "th":

macro Stephens_monoclinic(s400, s040, s004, s220, s202, s022, s301, s121, s103, eta)
{
prm mhkl = H⁴ s400 + K⁴ s040 + L⁴ s004 +
H² K² s220 + H² L² s202 + K² L² s022 +
H K² L s121 +
H L³ s103 + H³ L s301;

prm pp = D_spacing² * Sqrt(Max(mhkl,0)) / 1000;

gauss_fwhm = 1.8/3.1415927 pp (1-eta) Tan(Th) + 0.0001;
lor_fwhm = 1.8/3.1415927 pp eta Tan(Th) + 0.0001;
}

We are presently trying to edit this macro to be compatible with our TOF data, but have not had any success. We are effectively trying to combine the TOF_x_axis_calibration macro with Stephens.

As WISH is multibank (i.e. each bank has its own set of t0, t1, t2 e.t.c), which are fit as part of the standard refinement (NaCaAlF) (and then t1/t2 against the sample in later stages), it isn't an option for us to just convert the data from TOF to 2theta, then read that in. (We're not entirely certain of what the implications of this are, and whether this would result in a high degree of correlation between those refined parameters, and those exclusive to this macro...)

This is the current amalgamation of macros:

macro TOF_Stephens_monoclinic(s400, s040, s004, s220, s202, s022, s301, s121, s103, eta, t0, t0v, t1, t1v, t2, t2v)
{

prm mhkl = H⁴ s400 + K⁴ s040 + L⁴ s004 +
H² K² s220 + H² L² s202 + K² L² s022 +
H K² L s121 +
H L³ s103 + H³ L s301;

prm pp = D_spacing² * Sqrt(Max(mhkl,0)) / 1000;

pk_xo = CeV(t0,t0v) + CeV(t1,t1v) D_spacing + CeV(t2,t2v) D_spacing²;

'note flightpath, t0, t1, t2 defined locally for each bank's xdd
prm !mytheta = ArcSin(pk_xo/505.56flightpathD_spacing);

gauss_fwhm = 1.8/3.1415927 pp (1-eta) Tan(mytheta) + 0.0001;
low_fwhm = 1.8/3.1415927 pp eta Tan(mytheta) + 0.0001;
}

Which is giving the following error:

"Cannot find match for macro TOF_Stephens_monoclinic
Number of arguements 20"

I also tried this with the whole TOF_x_axis_calibration macro in there, but got the same error.

Has anybody tried this before/can explain the errors I'm making above? Apologies if this is an obvious fix, I am not as familiar with the syntax of TOPAS as I would like to be!

Thanks in advance,
James

jmas5

Have realised that the formatting above automatically italicises anything inside *'s. Where above random lines are in italic, that represents: asterisk xyz asterisk

rowlesmr

I'm not commenting your amalgamation, as I'm not qualified.

How are you calling your TOF macro? It has 16 arguments. The error

"Cannot find match for macro TOF_Stephens_monoclinic
Number of arguements 20"

says that you're calling it in your code with 20 arguments, and TOPAS can't find a macro called "TOF_Stephens_monoclinic" which takes 20 arguments.

johnsoevans

In tof you can just use D_spacing which topas will know for each hkl instead of tan Th. You don’t need to send over calibration constants. This is covered (more or less) in the last section of chapter 4 in the topas/Rietveld text book.

jmas5

Hi Both,

Thanks for your help here. I have modified the original stephens macro to replace tan Th with D_spacing as suggested:

macro TOF_Stephens_monoclinic(s400, s040, s004, s220, s202, s022, s301, s121, s103, eta)
{
prm mhkl = H4 s400 + K4 s040 + L4 s004 +
H2 K2 s220 + H2 L2 s202 + K2 L2 s022 +
H K2 L s121 +
H L3 s103 + H3 L s301;

prm pp = D_spacing2 * Sqrt(Max(mhkl,0)) / 1000;

gauss_fwhm = 1.8/3.1415927 pp (1-eta) D_spacing + 0.0001;
lor_fwhm = 1.8/3.1415927 pp eta D_spacing + 0.0001;
}

Which I am calling as such in the refinement (note for the XRD I call "Stephens_monoclinic" in this same way, with no issues):

TOF_Stephens_monoclinic
(
eta, 0.5,
s400, 200,
s040, 200,
s004, 200,
s220, 200,
s202, 200,
s022, 200,
s121, 200,
s103, 200,
s301, 200
)

However, I'm still receiving the same error message:

"Cannot find match for macro TOF_Stephens_monoclinic
Number of arguements 20"

As suggested above, it is saying that it cannot find this macro, which takes 20 arguments (corresponding to the 10 parameter names and 10 parameter values in the called macro).

I'm defining this, as I would any temporary macro, at the top of the file (as opposed to in the .inc). This works just fine for the other macros I have defined this way, such as the below:

macro Out_Tick_XRD_Q(file)
{
phase_out file load out_record out_fmt out_eqn
{
" %11.5f 200\n" = 2 *Pi / D_spacing;
}
}

Is there any reason why TOPAS would not be recognising this user defined macro? I have tried changing the name in case there is anything special about it, but I receive the same error, only with the new name. Functionally, the only differences between the macro I am trying to use (unsuccessfully), and the default stephens_monoclinic, is the new name, and the replacement of tan Th with D_spacing.

Checking the stephens_monoclinic macro in our topas.inc (V7) actually shows it is a bit different to that on the topas website:

macro Stephens_monoclinic
(
etac, etav,
s400c,s400v,
s040c,s040v,
s004c,s004v,
s220c,s220v,
s202c,s202v,
s022c,s022v,
s121c,s121v,
s103c,s103v,
s301c,s301v
)
{
#m_argu s400c If_Prm_Eqn_Rpt(s400c, s400v,)
#m_argu s040c If_Prm_Eqn_Rpt(s040c, s040v,)
#m_argu s004c If_Prm_Eqn_Rpt(s004c, s004v,)
#m_argu s220c If_Prm_Eqn_Rpt(s220c, s220v,)
#m_argu s202c If_Prm_Eqn_Rpt(s202c, s202v,)
#m_argu s022c If_Prm_Eqn_Rpt(s022c, s022v,)
#m_argu s121c If_Prm_Eqn_Rpt(s121c, s121v,)
#m_argu s103c If_Prm_Eqn_Rpt(s103c, s103v,)
#m_argu s301c If_Prm_Eqn_Rpt(s301c, s301v,)
Stephens_lor_gauss(
etac, etav,
CeV(s400c,s400v) H⁴ +
CeV(s040c,s040v) K⁴ +
CeV(s004c,s004v) L⁴ +
CeV(s220c,s220v) H² K² +
CeV(s202c,s202v) H² L² +
CeV(s022c,s022v) K² L² +
CeV(s121c,s121v) H K² L +
CeV(s103c,s103v) H L³ +
CeV(s301c,s301v) H³ L
)
}

I am a little confused, as this seems to entirely remove reference to the tan Th, which we thought was causing the TOF incompatibility to begin with. Apologies for the wall of text, if you have any suggestions for why this might still not be working, any advice greatly appreciated!

Thanks again for your time and help!

johnsoevans

I think you're just missing a #m_argu for (eta,etav) which is in your macro call.

rowlesmr

So you have defined a macro

macro TOF_Stephens_monoclinic(s400, s040, s004, s220, s202, s022, s301, s121, s103, eta)
{
prm mhkl = H4 s400 + K4 s040 + L4 s004 +
H2 K2 s220 + H2 L2 s202 + K2 L2 s022 +
H K2 L s121 +
H L3 s103 + H3 L s301;

prm pp = D_spacing2 * Sqrt(Max(mhkl,0)) / 1000;

gauss_fwhm = 1.8/3.1415927 pp (1-eta) D_spacing + 0.0001;
lor_fwhm = 1.8/3.1415927 pp eta D_spacing + 0.0001;
}

which you are then calling in your input file as

TOF_Stephens_monoclinic(eta, 0.5, s400, 200, s040, 200, s004, 200, s220, 200, s202, 200, s022, 200, s121, 200, s103, 200, s301, 200)

Is that correct?

Well, there's your problem. You've defined a macro with 10 arguments and are calling it with 20. TOPAS then complains that it can't find a macro definition with 20 arguments because you haven't provided one.