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== Referensi ==
== Referensi ==
*{{Citation | last1=Barlow | first1=W | title=Über die geometrischen Eigenschaften starrer Strukturen und ihre Anwendung auf Kristalle |trans-title=On the geometric properties of rigid structures and their application to crystals | year=1894 | journal=Zeitschrift für Kristallographie | volume=23 | pages=1–63 | doi=10.1524/zkri.1894.23.1.1| s2cid=102301331 | url=https://zenodo.org/record/1448950 }}
*{{Citation | last1=Barlow | first1=W | title=Über die geometrischen Eigenschaften starrer Strukturen und ihre Anwendung auf Kristalle | trans-title=On the geometric properties of rigid structures and their application to crystals | year=1894 | journal=Zeitschrift für Kristallographie | volume=23 | pages=1–63 | doi=10.1524/zkri.1894.23.1.1 | s2cid=102301331 | url=https://zenodo.org/record/1448950 | accessdate=2021-05-11 | archive-date=2023-04-18 | archive-url=https://web.archive.org/web/20230418225208/https://zenodo.org/record/1448950 | dead-url=no }}
*{{Citation | last1=Bieberbach | first1=Ludwig | title=Über die Bewegungsgruppen der Euklidischen Räume |trans-title=On the groups of [[rigid transformation]]s in Euclidean spaces | doi=10.1007/BF01564500 | year=1911 | journal=[[Mathematische Annalen]] | issn=0025-5831 | volume=70 | issue=3 | pages=297–336| s2cid=124429194 }}
*{{Citation | last1=Bieberbach | first1=Ludwig | title=Über die Bewegungsgruppen der Euklidischen Räume |trans-title=On the groups of [[rigid transformation]]s in Euclidean spaces | doi=10.1007/BF01564500 | year=1911 | journal=[[Mathematische Annalen]] | issn=0025-5831 | volume=70 | issue=3 | pages=297–336| s2cid=124429194 }}
*{{Citation | last1=Bieberbach | first1=Ludwig | title=Über die Bewegungsgruppen der Euklidischen Räume (Zweite Abhandlung.) Die Gruppen mit einem endlichen Fundamentalbereich |trans-title=On the groups of [[rigid transformation]]s in Euclidean spaces (Second essay.) Groups with a finite fundamental domain | doi=10.1007/BF01456724 | year=1912 | journal=[[Mathematische Annalen]] | issn=0025-5831 | volume=72 | issue=3 | pages=400–412| s2cid=119472023 | url=https://zenodo.org/record/2435214 }}
*{{Citation | last1=Bieberbach | first1=Ludwig | title=Über die Bewegungsgruppen der Euklidischen Räume (Zweite Abhandlung.) Die Gruppen mit einem endlichen Fundamentalbereich | trans-title=On the groups of [[rigid transformation]]s in Euclidean spaces (Second essay.) Groups with a finite fundamental domain | doi=10.1007/BF01456724 | year=1912 | journal=[[Mathematische Annalen]] | issn=0025-5831 | volume=72 | issue=3 | pages=400–412 | s2cid=119472023 | url=https://zenodo.org/record/2435214 | accessdate=2021-05-11 | archive-date=2023-04-18 | archive-url=https://web.archive.org/web/20230418021519/https://zenodo.org/record/2435214 | dead-url=no }}
*{{Citation | last1=Brown | first1=Harold | last2=Bülow | first2=Rolf | last3=Neubüser | first3=Joachim | last4=Wondratschek | first4=Hans | last5=Zassenhaus | first5=Hans | author5-link=Hans Zassenhaus | title=Crystallographic groups of four-dimensional space | publisher=Wiley-Interscience [John Wiley & Sons] | location=New York | isbn=978-0-471-03095-9 |mr=0484179 | year=1978}}
*{{Citation | last1=Brown | first1=Harold | last2=Bülow | first2=Rolf | last3=Neubüser | first3=Joachim | last4=Wondratschek | first4=Hans | last5=Zassenhaus | first5=Hans | author5-link=Hans Zassenhaus | title=Crystallographic groups of four-dimensional space | publisher=Wiley-Interscience [John Wiley & Sons] | location=New York | isbn=978-0-471-03095-9 |mr=0484179 | year=1978}}
*{{Citation | last1=Burckhardt | first1=Johann Jakob | title=Die Bewegungsgruppen der Kristallographie |trans-title=Groups of [[Rigid Transformation]]s in Crystallography | publisher=Verlag Birkhäuser, Basel | series=Lehrbücher und Monographien aus dem Gebiete der exakten Wissenschaften (Textbooks and Monographs from the Fields of the Exact Sciences) |mr=0020553 | year=1947 | volume=13}}
*{{Citation | last1=Burckhardt | first1=Johann Jakob | title=Die Bewegungsgruppen der Kristallographie |trans-title=Groups of [[Rigid Transformation]]s in Crystallography | publisher=Verlag Birkhäuser, Basel | series=Lehrbücher und Monographien aus dem Gebiete der exakten Wissenschaften (Textbooks and Monographs from the Fields of the Exact Sciences) |mr=0020553 | year=1947 | volume=13}}
*{{Citation | last1=Burckhardt | first1=Johann Jakob | title=Zur Geschichte der Entdeckung der 230 Raumgruppen |trans-title=On the history of the discovery of the 230 space groups | doi=10.1007/BF00412962 |mr=0220837 | year=1967 | journal=[[Archive for History of Exact Sciences]] | issn=0003-9519 | volume=4 | issue=3 | pages=235–246| s2cid=121994079 }}
*{{Citation | last1=Burckhardt | first1=Johann Jakob | title=Zur Geschichte der Entdeckung der 230 Raumgruppen |trans-title=On the history of the discovery of the 230 space groups | doi=10.1007/BF00412962 |mr=0220837 | year=1967 | journal=[[Archive for History of Exact Sciences]] | issn=0003-9519 | volume=4 | issue=3 | pages=235–246| s2cid=121994079 }}
*{{Citation | last1=Conway | first1=John Horton | author1-link=John Horton Conway | last2=Delgado Friedrichs | first2=Olaf | last3=Huson | first3=Daniel H. | last4=Thurston | first4=William P. | author4-link=William Thurston | title=On three-dimensional space groups | url=http://www.emis.de/journals/BAG/vol.42/no.2/17.html |mr=1865535 | year=2001 | journal=Beiträge zur Algebra und Geometrie | issn=0138-4821 | volume=42 | issue=2 | pages=475–507}}
*{{Citation | last1=Conway | first1=John Horton | author1-link=John Horton Conway | last2=Delgado Friedrichs | first2=Olaf | last3=Huson | first3=Daniel H. | last4=Thurston | first4=William P. | author4-link=William Thurston | title=On three-dimensional space groups | url=http://www.emis.de/journals/BAG/vol.42/no.2/17.html | mr=1865535 | year=2001 | journal=Beiträge zur Algebra und Geometrie | issn=0138-4821 | volume=42 | issue=2 | pages=475–507 | accessdate=2021-05-11 | archive-date=2021-04-18 | archive-url=https://web.archive.org/web/20210418133128/https://www.emis.de/journals/BAG/vol.42/no.2/17.html | dead-url=no }}
*{{Citation | last1=Fedorov | first1=E. S. | title=Симметрія правильныхъ системъ фигуръ |trans-title=''Simmetriya pravil'nykh sistem figur'', The symmetry of regular systems of figures | year=1891 | journal=Записки Императорского С.-Петербургского Минералогического Общества (Zapiski Imperatorskova Sankt Petersburgskova Mineralogicheskova Obshchestva, Proceedings of the Imperial St. Petersburg Mineralogical Society) | series=2nd series | volume=28 | issue=2 | pages=1–146 |url=https://babel.hathitrust.org/cgi/pt?id=umn.31951t00080576a;view=1up;seq=11 }}
*{{Citation | last1=Fedorov | first1=E. S. | title=Симметрія правильныхъ системъ фигуръ | trans-title=''Simmetriya pravil'nykh sistem figur'', The symmetry of regular systems of figures | year=1891 | journal=Записки Императорского С.-Петербургского Минералогического Общества (Zapiski Imperatorskova Sankt Petersburgskova Mineralogicheskova Obshchestva, Proceedings of the Imperial St. Petersburg Mineralogical Society) | series=2nd series | volume=28 | issue=2 | pages=1–146 | url=https://babel.hathitrust.org/cgi/pt?id=umn.31951t00080576a;view=1up;seq=11 | accessdate=2021-05-11 | archive-date=2023-04-15 | archive-url=https://web.archive.org/web/20230415005649/https://babel.hathitrust.org/cgi/pt?id=umn.31951t00080576a;view=1up;seq=11 | dead-url=no }}
*{{Citation | last1=Fedorov | first1=E. S. | title=Symmetry of crystals | publisher=American Crystallographic Association | series=ACA Monograph | year=1971 | volume=7}}
*{{Citation | last1=Fedorov | first1=E. S. | title=Symmetry of crystals | publisher=American Crystallographic Association | series=ACA Monograph | year=1971 | volume=7}}
*{{Citation | editor1-last=Hahn | editor1-first=Theo | title=International Tables for Crystallography, Volume A: Space Group Symmetry | url=http://it.iucr.org/A/ | publisher=[[Springer-Verlag]] | location=Berlin, New York | edition=5th | isbn=978-0-7923-6590-7 | doi=10.1107/97809553602060000100 | year=2002 | last1=Hahn | first1=Th. | volume=A| series=International Tables for Crystallography }}
*{{Citation | editor1-last=Hahn | editor1-first=Theo | title=International Tables for Crystallography, Volume A: Space Group Symmetry | url=http://it.iucr.org/A/ | publisher=[[Springer-Verlag]] | location=Berlin, New York | edition=5th | isbn=978-0-7923-6590-7 | doi=10.1107/97809553602060000100 | year=2002 | last1=Hahn | first1=Th. | volume=A | series=International Tables for Crystallography | accessdate=2021-05-11 | archive-date=2021-04-28 | archive-url=https://web.archive.org/web/20210428051623/https://it.iucr.org/A/ | dead-url=no }}
*{{Citation | last1=Hall | first1=S.R. | title=Space-Group Notation with an Explicit Origin | journal=Acta Crystallographica A |volume=37 | issue=4 | pages=517–525 | year=1981|doi=10.1107/s0567739481001228 |bibcode = 1981AcCrA..37..517H }}
*{{Citation | last1=Hall | first1=S.R. | title=Space-Group Notation with an Explicit Origin | journal=Acta Crystallographica A |volume=37 | issue=4 | pages=517–525 | year=1981|doi=10.1107/s0567739481001228 |bibcode = 1981AcCrA..37..517H }}
*{{citation |last1=Janssen |first1=T. |author-link=Ted Janssen |last2=Birman| first2=J.L. |last3=Dénoyer|first3=F.|last4=Koptsik|first4=V.A. |last5=Verger-Gaugry| first5=J.L. |last6=Weigel|first6=D.|last7=Yamamoto|first7=A. |last8=Abrahams| first8=S.C. |last9=Kopsky|first9=V.|title=Report of a Subcommittee on the Nomenclature of ''n''-Dimensional Crystallography. II. Symbols for arithmetic crystal classes, Bravais classes and space groups |journal=Acta Crystallographica A |volume=58 |issue=Pt 6 |pages=605–621 |year=2002 |doi=10.1107/S010876730201379X |pmid=12388880 |doi-access=free }}
*{{citation |last1=Janssen |first1=T. |author-link=Ted Janssen |last2=Birman| first2=J.L. |last3=Dénoyer|first3=F.|last4=Koptsik|first4=V.A. |last5=Verger-Gaugry| first5=J.L. |last6=Weigel|first6=D.|last7=Yamamoto|first7=A. |last8=Abrahams| first8=S.C. |last9=Kopsky|first9=V.|title=Report of a Subcommittee on the Nomenclature of ''n''-Dimensional Crystallography. II. Symbols for arithmetic crystal classes, Bravais classes and space groups |journal=Acta Crystallographica A |volume=58 |issue=Pt 6 |pages=605–621 |year=2002 |doi=10.1107/S010876730201379X |pmid=12388880 |doi-access=free }}
*{{Citation | last1=Kim | first1=Shoon K. | title=Group theoretical methods and applications to molecules and crystals | publisher=[[Cambridge University Press]] | isbn=978-0-521-64062-6 |mr=1713786 | year=1999 | doi=10.1017/CBO9780511534867| s2cid=117849701 | url=https://semanticscholar.org/paper/c87bb39c5bf963620ac51edf27b1b8924d414ae5 }}
*{{Citation | last1=Kim | first1=Shoon K. | title=Group theoretical methods and applications to molecules and crystals | publisher=[[Cambridge University Press]] | isbn=978-0-521-64062-6 | mr=1713786 | year=1999 | doi=10.1017/CBO9780511534867 | s2cid=117849701 | url=https://semanticscholar.org/paper/c87bb39c5bf963620ac51edf27b1b8924d414ae5 | accessdate=2021-05-11 | archive-date=2023-08-09 | archive-url=https://web.archive.org/web/20230809154103/https://www.semanticscholar.org/paper/Group-Theoretical-Methods-and-Applications-to-and-Kim/c87bb39c5bf963620ac51edf27b1b8924d414ae5 | dead-url=no }}
*{{citation |last=Litvin |first=D.B. |title=Tables of crystallographic properties of magnetic space groups |journal=Acta Crystallographica A |volume=64 |issue=Pt 3 |pages=419–24 |date=May 2008 |pmid=18421131 |doi=10.1107/S010876730800768X |bibcode = 2008AcCrA..64..419L }}
*{{citation |last=Litvin |first=D.B. |title=Tables of crystallographic properties of magnetic space groups |journal=Acta Crystallographica A |volume=64 |issue=Pt 3 |pages=419–24 |date=May 2008 |pmid=18421131 |doi=10.1107/S010876730800768X |bibcode = 2008AcCrA..64..419L }}
*{{citation |last=Litvin |first=D.B. |title=Tables of properties of magnetic subperiodic groups |journal=Acta Crystallographica A |volume=61 |issue=Pt 3 |pages=382–5 |date=May 2005 |pmid=15846043 |doi=10.1107/S010876730500406X |bibcode=2005AcCrA..61..382L |url=http://www.ccp14.ac.uk/ccp/web-mirrors/daniel_litvin/faculty/litvin/P_paper_96.pdf |accessdate=2021-05-11 |archive-date=2017-08-10 |archive-url=https://web.archive.org/web/20170810044609/http://www.ccp14.ac.uk/ccp/web-mirrors/daniel_litvin/faculty/litvin/P_paper_96.pdf |dead-url=yes }}
*{{citation |last=Litvin |first=D.B. |title=Tables of properties of magnetic subperiodic groups |journal=Acta Crystallographica A |volume=61 |issue=Pt 3 |pages=382–5 |date=May 2005 |pmid=15846043 |doi=10.1107/S010876730500406X |bibcode=2005AcCrA..61..382L |url=http://www.ccp14.ac.uk/ccp/web-mirrors/daniel_litvin/faculty/litvin/P_paper_96.pdf |accessdate=2021-05-11 |archive-date=2017-08-10 |archive-url=https://web.archive.org/web/20170810044609/http://www.ccp14.ac.uk/ccp/web-mirrors/daniel_litvin/faculty/litvin/P_paper_96.pdf |dead-url=yes }}
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*{{Citation | last1=Palistrant| first1=A. F. | title= Complete Scheme of Four-Dimensional Crystallographic Symmetry Groups | year=2012| journal=Crystallography Reports | volume=57 | issue=4 | pages=471–477 | doi=10.1134/S1063774512040104| bibcode=2012CryRp..57..471P| s2cid=95680790 }}
*{{Citation | last1=Palistrant| first1=A. F. | title= Complete Scheme of Four-Dimensional Crystallographic Symmetry Groups | year=2012| journal=Crystallography Reports | volume=57 | issue=4 | pages=471–477 | doi=10.1134/S1063774512040104| bibcode=2012CryRp..57..471P| s2cid=95680790 }}
*{{Citation | last1=Plesken | first1=Wilhelm | last2=Hanrath | first2=W| title=The lattices of six-dimensional space | year=1984 | journal=Math. Comp. | volume=43 | issue=168 | pages=573–587 | doi=10.1090/s0025-5718-1984-0758205-5| doi-access=free }}
*{{Citation | last1=Plesken | first1=Wilhelm | last2=Hanrath | first2=W| title=The lattices of six-dimensional space | year=1984 | journal=Math. Comp. | volume=43 | issue=168 | pages=573–587 | doi=10.1090/s0025-5718-1984-0758205-5| doi-access=free }}
*{{Citation | last1=Plesken | first1=Wilhelm | last2=Schulz | first2=Tilman | title=Counting crystallographic groups in low dimensions | url=http://projecteuclid.org/euclid.em/1045604675 |mr=1795312 | year=2000 | journal=Experimental Mathematics | issn=1058-6458 | volume=9 | issue=3 | pages=407–411 | doi=10.1080/10586458.2000.10504417| s2cid=40588234 }}
*{{Citation | last1=Plesken | first1=Wilhelm | last2=Schulz | first2=Tilman | title=Counting crystallographic groups in low dimensions | url=http://projecteuclid.org/euclid.em/1045604675 | mr=1795312 | year=2000 | journal=Experimental Mathematics | issn=1058-6458 | volume=9 | issue=3 | pages=407–411 | doi=10.1080/10586458.2000.10504417 | s2cid=40588234 | accessdate=2021-05-11 | archive-date=2021-04-18 | archive-url=https://web.archive.org/web/20210418133111/https://projecteuclid.org/euclid.em/1045604675 | dead-url=no }}
*{{Citation | last1=Schönflies | first1=Arthur Moritz | title=Theorie der Kristallstruktur |trans-title=Theory of Crystal Structure | year=1923 | journal=Gebrüder Bornträger, Berlin.}}
*{{Citation | last1=Schönflies | first1=Arthur Moritz | title=Theorie der Kristallstruktur |trans-title=Theory of Crystal Structure | year=1923 | journal=Gebrüder Bornträger, Berlin.}}
*{{Citation | last1=Souvignier| first1=Bernd| title=The four-dimensional magnetic point and space groups | year=2006 | journal=Zeitschrift für Kristallographie | volume=221 | pages=77–82 | doi=10.1524/zkri.2006.221.1.77|bibcode = 2006ZK....221...77S | s2cid=99946564}}
*{{Citation | last1=Souvignier| first1=Bernd| title=The four-dimensional magnetic point and space groups | year=2006 | journal=Zeitschrift für Kristallographie | volume=221 | pages=77–82 | doi=10.1524/zkri.2006.221.1.77|bibcode = 2006ZK....221...77S | s2cid=99946564}}
*{{eom|id=C/c027190|title=Crystallographic group|last=Vinberg|first=E.}}
*{{eom|id=C/c027190|title=Crystallographic group|last=Vinberg|first=E.}}
*{{Citation | doi=10.1007/BF02568029 | last1=Zassenhaus | first1=Hans | author1-link=Hans Zassenhaus | title=Über einen Algorithmus zur Bestimmung der Raumgruppen |trans-title=On an algorithm for the determination of space groups | url=http://www.digizeitschriften.de/index.php?id=166&ID=380406 |mr=0024424 | year=1948 | journal=Commentarii Mathematici Helvetici | issn=0010-2571 | volume=21 | pages=117–141| s2cid=120651709 }}
*{{Citation | doi=10.1007/BF02568029 | last1=Zassenhaus | first1=Hans | author1-link=Hans Zassenhaus | title=Über einen Algorithmus zur Bestimmung der Raumgruppen | trans-title=On an algorithm for the determination of space groups | url=http://www.digizeitschriften.de/index.php?id=166&ID=380406 | mr=0024424 | year=1948 | journal=Commentarii Mathematici Helvetici | issn=0010-2571 | volume=21 | pages=117–141 | s2cid=120651709 | accessdate=2021-05-11 | archive-date=2012-11-28 | archive-url=https://web.archive.org/web/20121128074147/http://www.digizeitschriften.de/index.php?id=166&ID=380406 | dead-url=no }}
*{{Citation | last1=Souvignier| first1=Bernd| title=Enantiomorphism of crystallographic groups in higher dimensions with results in dimensions up to 6 | year=2003 | journal=Acta Crystallographica A| volume=59 | issue=3| pages=210–220 | doi=10.1107/S0108767303004161| pmid=12714771}}
*{{Citation | last1=Souvignier| first1=Bernd| title=Enantiomorphism of crystallographic groups in higher dimensions with results in dimensions up to 6 | year=2003 | journal=Acta Crystallographica A| volume=59 | issue=3| pages=210–220 | doi=10.1107/S0108767303004161| pmid=12714771}}



Revisi terkini sejak 9 Agustus 2023 15.41

Grup ruang sebuah kristal adalah deskripsi matematis dari simetri dalam struktur. Kata 'grup' dalam istilah ini berasal dari istilah matematika grup, yang digunakan untuk membangun set grup ruang.

Seluruh 230 set grup ruang diperoleh dari kombinasi 32 grup titik kristalografi dengan 14 kisi Bravais yang termasuk dalam salah satu dari 7 sistem kristal. Hasil ini dalam grup ruang yang adalah kombinasi dari sebuah sel unit dengan beberapa bentuk dari pemusatan motif, bersamaan dengan operasi – operasi titik pencerminan, rotasi, dan improper rotation. Selain itu, terdapat juga elemen simetri translasi. Translasi dasar diperoleh dari tipe kisi, menyisakan kombinasi pencerminan dan rotasi dengan translasi:

Sumbur mur: Sebuah rotasi pada suatu sumbu, diikuti dengan translasi sepanjang arah sumbu. Sumbu ini diberi angka, n, untuk mendeskripsikan derajat rotasi, dan angka yang diberikan menunjukkan berapa banyak operasi yang harus dilakukan untuk menyelesaikan satu putaran penuh (sebagai contoh, 3 berarti setiap kali rotasi dilakukan 1/3 keliling sumbu). Derajat translasi kemudian ditambahkan sebagai subskrip untuk menunjukkan seberapa jauh translasi sepanjang sumbu dilakukan, sebagai bagian dari vektor kisi paralel. Jadi, 21 adalah rotasi lipat dua yang diikuti oleh translasi sebesar 1/2 dari vektor kisi.

Bidang geser: Sebuah pencerminan pada bidang, diikuti oleh translasi yang paralel terhadap bidang tersebut. Hal ini ditandai oleh a, b, atau c, bergantung pada sumbu mana dilakukan penggeseran. Terdapat juga geseran n, yaitu geseran sepanjang setengan diagonal muka, dan geseran d, yaitu geseran sepanjang 1/4 diagonal muka sel unit.

Sangat mudah ditemukan bahwa tidak semua kombinasi yang mungkin dari kisi-kisi Bravais, sistem-sistem kristal dan grup-grup titik muncul pada grup ruang (32*14=448>230). Hal ini disebabkan oleh adanya beberapa kombinasi berbeda yang isomorfik satu dengan lainnya (yaitu mereka ternyata adalah hal yang sama). Hal ini dibuktikan menggunakan teori grup, dan adalah sumber dari kata 'grup' pada judul.

Terdapat beberapa metode untuk menguidentifikasi grup ruang. International Union of Chrystallography menerbitkan sebuah tabel (lebih tepatnya, sebuah kitab tabel – tabel) untuk semua grup ruang, dan memberikan nomor yang unik untuk masing – masing grup ruang. Selain cara penomoran, ada dua bentuk notasi utama, notasi Patterson dan Scoenflies.

Notasi Patterson terdiri atas satu set empat simbol. Yang pertama menjelaskan pemusatan kisi Bravais (P, C, I atau F). Tiga angka selanjutnya menunjukkan operasi simetri yang paling jelas terlihat ketika diproyeksikan secara berurutan dari muka a, b, dan c. Simbol – simbol ini adalah sama dengan yang digunakan pada grup titik, ditambah bidang geser dan sumbu mur, yang dijelaskan di atas. Sebagai contoh, grup ruang untuk kwarsa adalah P3121, yang menunjukkan pemusatan motif sederhana (misal sekali per sel unit), dengan sumbu mur lipat tiga pada satu sisi dan sumbu rotasi lipat dua pada yang lain. Perlu diperhatikan bahwa notasi ini tidak secara eksplisit mengandung sistem kristal, walaupun notasi ini adalah unik untuk setiap grup ruang ( dalam hal P3121, P3121 adalah trigonal).

Referensi

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