密度の高い水素中の構造とバンドギャップの閉塞
1Laboratory of Atomic and Solid State Physics and Cornell Center for Materials Research, Cornell University, Ithaca, New York 14853-2501, USA.
Nature
|February 25, 2000
まとめ
1935年以来予測された金属水素は,未だに難解である. 密度関数計算は,特定の密度でペアメタリック状態が可能であることを示唆しているが,それを達成するには,現在の近似を超えた高度な計算方法が必要になる可能性がある.
科学分野:
- 凝縮物質物理学 凝縮物質物理学
- マテリアルサイエンス 材料科学
- 計算化学はコンピュータ化学である.
背景:
- 水素が極度の圧力下で金属状態への移行は,1935年以来理論化されてきました.
- 固体金属水素の実験的実現は,研究がわずか342GPaに達したため,挑戦的です.
- 水素の陽子対の絶縁体構造の頑丈さは,直接の金属化を複雑にする.
研究 の 目的:
- 密度の高い水素でペアまたは分子金属状態を達成するための条件を計算的に調査する.
- メタリック水素への代替経路を探求し,分子ペアリングを保ちます.
- 予測された過渡圧に対する多くの電子効果の影響を評価する.
主な方法:
- 局所密度近似 (LDA) 内の密度関数計算.
- バンド構造とバンドギャップの閉塞の分析.
- LDA.に近似された多くの電子の補正を加えた.
主要な成果:
- LDA計算は,ペアまたは分子金属水素状態がエネルギー的に好まれる密度の範囲を予測します.
- この金属状態への移行は,バンドギャップの閉鎖に関連しています.
- 多くの電子効果を補正すると,移行の予測圧力が大きく変化します.
結論:
- 水素のペア化または分子金属状態は,特定の密度条件下では計算的に妥当である.
- 金属水素の正確な予測には,標準のLDAを超えて,多くの電子効果を組み込む必要があります.
- 密度の高い水素の相図を完全に解明するには,さらなる理論的発展が必要である.
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