# Incommensurately modulated structures of the                    <i>M</i>                    <sub>1/8</sub>                    Pr                    <sub>5/8</sub>                    MoO                    <sub>4</sub>                    (                    <i>M</i>                    = Li, Na, K) scheelites

https://mdr.nims.go.jp/datasets/b05e3618-5ebf-449a-9eab-8d5af088a6ca

## File

- [Acta Cryst-B82-120-130-MPr5(MoO4)8.pdf](https://mdr.nims.go.jp/filesets/3df95a03-d18d-4972-9928-b5daaa60fd34/download) ([Detail](https://mdr.nims.go.jp/filesets/3df95a03-d18d-4972-9928-b5daaa60fd34.md))

## Id

b05e3618-5ebf-449a-9eab-8d5af088a6ca

## Local identifier



## Visibility

open_to_public

## State

published

## Created at

2026-04-16T06:12:28.485650Z

## Updated at

2026-04-16T07:16:01.927279Z

## Published at

2026-04-16T09:27:26.821894Z

## Doi



## First published url

https://doi.org/10.1107/s2052520626000375

## Date published

2026-04-01

## Recorded date published



## Resource type

journal_article

## Manuscript type

vor

## Collection



## Title

- title: |-
    Incommensurately modulated structures of the
                        <i>M</i>
                        <sub>1/8</sub>
                        Pr
                        <sub>5/8</sub>
                        MoO
                        <sub>4</sub>
                        (
                        <i>M</i>
                        = Li, Na, K) scheelites
  title_type: original
  lang: en

## Description

- description: The effect of cation substitutions in the scheelite-type framework
    is investigated to understand the ordering of M+/Pr3+ cations and vacancies in
    the structure. The cation deficient M1/8Pr5/8MoO4 (M = Li, Na, K) phases were
    synthesized using solid state reactions. The K:Pr ratio in the K1/8Pr5/8MoO4 sample
    was determined by inductively coupled plasma mass spectroscopy, inductively coupled
    plasma optical emission spectrometry and total reflection X-ray fluorescence spectroscopy.
    The local element distributions in K1/8Pr5/8MoO4 were determined by energy-dispersive
    X-ray spectrometry. The incommensurately modulated crystal structures of the scheelite-based
    M1/8Pr5/8MoO4 (M = Li, Na, K) phases were refined from synchrotron powder X-ray
    diffraction data. The analysis revealed that cation ordering in the M1/8Pr5/8MoO4
    (M = Li, Na) structures is incomplete and is more accurately described by continuous,
    rather than discontinuous (step-like), occupational modulation functions. The
    occupancy modulation waves for Li/Na and Pr atoms demonstrate an antiphase relation.
    Compared with M = Li, Na, the order of K and Pr cations in the A position in the
    K1/8Pr5/8MoO4 structure is best approximated by crenel functions. Refining the
    coordinates and lengths of three atomic domains yields the composition of K0.145Pr0.618MoO4.
    In all cases, the modulation arises from ordering of M/Pr cations and cation vacancies
    at the A-sublattice of the parent scheelite ABO4 structure. The distortion of
    PrO8 and MO8 polyhedra is practically independent of the radius of the M+ cations.
    The refinements of the M1/8Pr5/8MoO4 (M = Li, Na, K) structures reveal that MoO42-
    tetrahedra in these scheelite-type compounds demonstrate a flexible geometry.
    Both Mo-O bond distances and O-Mo-O bond angles vary significantly with changing
    the population of the A site by cations with different sizes.
  description_type: abstract
  lang: und

## Creator

- name: Vladimir A. Morozov
  role: author
- name: Dina V. Deyneko
  role: author
- name: Darya G. Filatova
  role: author
- name: Alexei A. Belik
  role: author
  orcid: https://orcid.org/0000-0001-9031-2355
  organization: National Institute for Materials Science
- name: Olga M. Basovich
  role: author
- name: Elena G. Khaikina
  role: author
- name: Bogdan I. Lazoryak
  role: author

## Contact agent



## Publisher

organization: International Union of Crystallography (IUCr)

## Managing organization



## Keyword

- subject: Incommensurate structures
  schema: not_defined
- subject: scheelite
  schema: not_defined
- subject: molybdates
  schema: not_defined

## Rights

- identifier: http://rightsstatements.org/vocab/InC/1.0/

## Other identifier(s)



## Data origin

- data_origin_type: other

## Embargo



## Journal

- title: Acta Crystallographica Section B Structural Science, Crystal Engineering
    and Materials
  issn: '20525206'
  volume: '82'
  issue: '2'
  start_page: 120
  end_page: 130

## Conference



## Related item



## Funding

- identifier: AAAA-A21-121011590086-0
  funder_name: State assignment "Substances and materials for ensuring safety, reliability
    and energy efficiency"
- funder_name: state assignment of the BINM SB RAS
- identifier: 2019A4501
  funder_name: NIMS Synchrotron X-ray Station

## Instrument



## Instrument operator



## Instrument managing organization



## Measurement method



## Specimen



## Chemical composition



## Structure for specimen



## Structural feature for specimen



## Specific property for specimen



## Process for specimen treatment



## Computational method



## Energy level/transition state



## Software



## Custom property



## Fileset

- id: 3df95a03-d18d-4972-9928-b5daaa60fd34
  filename: Acta Cryst-B82-120-130-MPr5(MoO4)8.pdf
  content_type: application/pdf
  size: 2171754
  md5: 2197ae28e828112841a1a753ce1524b6

## Thumbnail

fileset_id: 3df95a03-d18d-4972-9928-b5daaa60fd34
filename: Acta Cryst-B82-120-130-MPr5(MoO4)8.pdf