<p>This study investigates the self-assembly behavior and morphological stability of symmetric AB diblock copolymers via coarse-grained molecular dynamics simulations. We focus on the effects of segmental incompatibility associated with interfacial interaction strength (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">\({\varepsilon }_{(A,B)}\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mrow> <mi>ε</mi> </mrow> <mrow> <mo>(</mo> <mi>A</mi> <mo>,</mo> <mi>B</mi> <mo>)</mo> </mrow> </msub> </math></EquationSource> </InlineEquation>), interaction range (<InlineEquation ID="IEq2"> <EquationSource Format="TEX">\({r}_{c,(B,B)}\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mrow> <mi>r</mi> </mrow> <mrow> <mi>c</mi> <mo>,</mo> <mo>(</mo> <mi>B</mi> <mo>,</mo> <mi>B</mi> <mo>)</mo> </mrow> </msub> </math></EquationSource> </InlineEquation>), and degree of polymerization (<i>N</i>) on the system morphology. By systematically varying these Lennard-Jones parameters governing intermolecular interactions, we quantify the resulting morphologies using domain spacing (<i>D</i>), the peak intensity of the structure factor <i>S</i>(<i>q*</i>), and the correlation length (<InlineEquation ID="IEq3"> <EquationSource Format="TEX">\({\xi }_{\text{fit}}\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mrow> <mi>ξ</mi> </mrow> <mrow> <mtext>fit</mtext> </mrow> </msub> </math></EquationSource> </InlineEquation>). Our results reveal that enhanced B-block cohesive interactions by increasing the range of intermolecular interactions (<InlineEquation ID="IEq4"> <EquationSource Format="TEX">\({r}_{c,(B,B)}\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mrow> <mi>r</mi> </mrow> <mrow> <mi>c</mi> <mo>,</mo> <mo>(</mo> <mi>B</mi> <mo>,</mo> <mi>B</mi> <mo>)</mo> </mrow> </msub> </math></EquationSource> </InlineEquation> <InlineEquation ID="IEq5"> <EquationSource Format="TEX">\(\ge\)</EquationSource> <EquationSource Format="MATHML"><math> <mo>≥</mo> </math></EquationSource> </InlineEquation> 2.0) stabilize lamellar structures by suppressing curvature-induced instabilities and preserving domain periodicity, even at high miscibility between the A and B blocks. Correlation analysis reveals that longer chain lengths and extended cohesive ranges synergistically enhance long-range ordering and interdomain connectivity. This study establishes a quantitative computational framework linking intermolecular interaction parameters with microphase separation, offering a practical strategy for exploring nanoscale morphology in block copolymers via molecular simulations.</p>