在 Word 里选中需要修正的文本内容，Alt + F11 打开宏面板，然后把下面这段粘贴进去运行即可~

化学式或分子式数字下标修正.vb

Sub 下标修正()
    Dim x, Y, j, k As Integer
    Dim m, n As Long
    Dim char As String
    x = Selection.Start
    Y = Selection.End
    For j = x To Y Step 1
        Selection.Start = j - 1
        Selection.End = j
        char = Selection.Text
        n = InStr("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ))]", char)
        If n <> 0 Then
            Selection.Start = j
            Selection.End = j + 1
            char = Selection.Text
            m = InStr("0123456789", char)
            If m <> 0 Then
                k = 2
                Selection.Font.Subscript = wdToggle
                Selection.Start = j
                Selection.End = j + k
                char = Selection.Characters(k).Text
                m = InStr("0123456789-+", char)
                Do While m <> 0
                    If char = "+" Or char = "-" Then
                        Selection.Start = j + k
                        Selection.End = j + k + 1
                        char = Selection.Text
                        m = InStr("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ(([", char)
                        If m <> 0 Then
                            GoTo LINE1
                        Else
                            Selection.Start = j - 1
                            Selection.End = j + k
                            char = Selection.Characters(1).Text
                        End If
                        If char = "O" Or char = "H" Then '与line1共同作用以防止将NH4+、AlO2-
                            Selection.Start = j
                            Selection.End = j + 1
                            Selection.Font.Subscript = wdToggle
                            Selection.Font.Subscript = wdToggle
                            Selection.Start = j + 1
                            Selection.End = j + k
                            Selection.Font.Superscript = wdToggle
                            GoTo LINE1
                        End If
                        Selection.Start = j
                        Selection.End = j + k
                        Selection.Font.Superscript = wdToggle
                        Selection.Font.Superscript = wdToggle
                        GoTo LINE1
                    End If
                    k = k + 1
                    Selection.Start = j
                    Selection.End = j + k
                    char = Selection.Characters(k).Text
                    If char = "-" Or char = "+" Then
                        Selection.Start = j
                        Selection.End = j + k - 2
                        Selection.Font.Subscript = wdToggle
                        Selection.Font.Subscript = wdToggle
                        Selection.Start = j + k - 2
                        Selection.End = j + k
                        Selection.Font.Superscript = wdToggle
                        GoTo LINE1
                    Else
                        m = InStr("0123456789", char)
                    End If
                Loop
                Selection.Start = j
                Selection.End = j + k - 1
                Selection.Font.Subscript = wdToggle
                Selection.Font.Subscript = wdToggle
            End If
LINE1:
            Selection.Start = j
            Selection.End = j + 1
            char = Selection.Text
            m = InStr("-", char)
            If m <> 0 Then
                Selection.Start = j + 1
                Selection.End = j + 2
                char = Selection.Text
                m = InStr("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ(([", char)
                If m = 0 Then
                    Selection.Start = j
                    Selection.End = j + 1
                    Selection.Font.Superscript = wdToggle
                End If
            End If
            m = InStr("+", char)
            If m <> 0 Then
                Selection.Start = j + 1
                Selection.End = j + 2
                char = Selection.Text
                m = InStr("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ(([+", char)
                If m = 0 Then
                    Selection.Start = j
                    Selection.End = j + 1
                    Selection.Font.Superscript = wdToggle
                End If
            End If
        End If
        Next j
        Selection.Start = Y
        Selection.End = Y
    End Sub