Table 2.

Optimized Geometrical Parameters of the Studied Compounds (Bond Length) Calculated by B3LYP Method with 6-311+G (d, p) basis set and VEDA 04.

Para- Xylene		3,6-Difluoro-Para-xylene		3,6-Dichloro-Para-xylene		3,6-Dibromo-Para-xylene
Bond Length	Value	Bond Length	Value	Bond Length	Value	Bond Length	Value
C1–C6	1.398	C1–C6	1.392	C1–C6	1.398	C1–C6	1.399
C1–C2	1.398	C1–C2	1.398	C1–C2	1.398	C1–C2	1.399
C1–C11	4.351	C1–C9	4.366	C1–C9	4.368	C1–C9	4.371
C6–H10	1.086	C6–F18	1.361	C6–Cl17	1.763	C6–Br18	1.923
C5–C4	1.398	C5–C4	1.398	C5–C4	1.398	C5–C4	1.399
C5–H9	1.086	C5–H8	1.084	C5–H8	1.083	C5–H8	1.083
C4–C3	1.398	C4–C3	1.392	C4–C3	1.398	C4–C3	1.397
C4–C15	4.351	C4–C13	4.366	C4–C13	4.368	C4–C13	4.371
C3–C2	1.393	C3–C2	1.385	C3–C2	1.39	C3–C2	1.39
C3–H8	1.086	C3–F17	1.361	C3–Cl18	1.763	C3–Br17	1.923
C2–H7	1.086	C2–H7	1.084	C2–H7	1.083	C2–H7	1.083
C11–H16	6.347	C9–H15	6.345	C9–H15	6.355	C9–H15	6.36
C11–H17	6.328	C9–H14	6.345	C9–H14	6.355	C9–H14	6.36
C11–H18	6.347	C9–H16	6.35	C9–H16	6.336	C9–H16	6.334
C15–H12	6.328	C13–H11	6.345	C13–H11	6.355	C13–H11	6.36
C15–H13	6.347	C13–H10	6.345	C13–H10	6.355	C13–H10	6.36
C15–H14	6.347	C13–H12	6.35	C13–H12	6.336	C13–H12	6.334